Next Article in Journal
InP-Based Waveguide Triple Transit Region Photodiodes for Hybrid Integration with Passive Optical Silica Waveguides
Previous Article in Journal
Optical Characteristics of a Multichannel Hybrid Integrated Light Source for Ultra-High-Bandwidth Optical Interconnections
Previous Article in Special Issue
Transient Response of Organo-Metal-Halide Solar Cells Analyzed by Time-Resolved Current-Voltage Measurements
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Photonics
Volume 2
Issue 4
10.3390/photonics2041139
photonics-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Stability Issues on Perovskite Solar Cells

by
Xing Zhao
and
Nam-Gyu Park
*
School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Korea
*
Author to whom correspondence should be addressed.
Photonics 2015, 2(4), 1139-1151; https://doi.org/10.3390/photonics2041139
Submission received: 3 November 2015 / Revised: 24 November 2015 / Accepted: 25 November 2015 / Published: 27 November 2015
(This article belongs to the Special Issue Perovskite Photovoltaic and Optoelectronics)
Browse Figures
Versions Notes

Abstract

:
Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3) and formamidinium lead iodide (HC(NH2)2PbI3) show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable nature of perovskite was observed when exposing it to continuous illumination, moisture and high temperature, impeding the commercial development in the long run and thus becoming the main issue that needs to be solved urgently. Here, we discuss the factors affecting instability of perovskite and give some perspectives about further enhancement of stability of perovskite solar cell.

1. Introduction

Perovskite solar cell (PSC) has attracted increasing attention due to the superb photovoltaic performance thanks to the intrinsic material properties with high absorption coefficient, balanced charge transport behavior and low trap density. PSCs based on liquid electrolytes were reported by Miyasaka et al. in 2009 [1], and by Park et al. in 2011 [2], where methylammonium lead halide (MAPbX3, MA = CH3NH3, X = I or Br) was used as an inorganic sensitizer similar to the organic sensitizer like N719 in dye-sensitized solar cell (DSSC) [3]. Low power conversion efficiency (PCE) of 3.8% reported in 2009 was because the precursor solution concentration of 8 wt% was too low to form dark color film, which was doubly improved by optimizing concentration to 40 wt%. However, liquid-type PSCs did not receive much attention because perovskite adsorbed on TiO2 was quickly dissolved by polar liquid electrolyte. Little attention had been paid to perovskite light absorbers until the discovery of solid-state PSC, reported by Park et al. in 2012 [4]. The basic structure of solid-state PSC comes from the solid-state DSSC employing organic hole transport material (HTM) of 2,2′,7,7′-tetrakis(N,N-dimethoxyphenylamine)-9,9′-spirobifluorene (spiro-MeOTAD) [5]. An all-solid-stated PSC with an efficiency of 9.7% was fabricated based on the sub-micrometer thick TiO2 whose surface was decorated with perovskite dots and the spiro-MeOTAD HTM (Figure 1). The device demonstrated 500 h-stability in air at room temperature, which was achieved without encapsulation. The excellent stability can be attributed to the utilization of the hydrophobic p-type spiro-MeOTAD that fully wrapped the perovskite dots. After that, Snaith et al. utilized the mesoporous Al2O3 as scaffold and achieved a PCE of 10.9% [6]. They found that the replacement of n-type mesoporous TiO2 with Al2O3 can improve the open circuit voltage (Voc). Almost at the same time, both Snaith’s group and Grätzel’s group achieved an efficiency of ~15% [7,8]. Meanwhile, formamidinium lead iodide (FAPbI3, FA = HC(NH2)2+) received less attention than MAPbI3 because of phase purity issue. Park et al. reported synthetic method of black polymorph FAPbI3, based on which the device showed a PCE of 16% [9]. By improving the quality and composition of FAPbI3 film, a PCE as high as 20.1% was achieved by Seok et al. in 2015 [10]. PSC opens now a new paradigm in photovoltaic area, which is evident because of a significant increase in the number of published research papers on this topic (Figure 2).
Photonics 02 01139 g001 1024
Figure 1. Solid-state device and its cross-sectional meso-structure. Reprinted with permission from reference [4].
Figure 1. Solid-state device and its cross-sectional meso-structure. Reprinted with permission from reference [4].
Photonics 02 01139 g001
The perovskite solar cells with high efficiencies, low cost, high stability, nontoxicity and reproducibility are our final goal to pursue. The fast progress in performance suggests that PSCs have great potential, surpassing the traditional silicon solar cells. Despite the high efficiency and relatively low cost, perovskite materials show unstable properties, which have become the main issues that need to be investigated and solved urgently. Chemical instability dramatically restricts the commercial development in the future. In order to understand the basis for the degradation of PSCs and solve it, three factors have been investigated: air (moisture and oxygen) stability, photo stability, and thermal stability. All of these factors should be taken into consideration for a high stability PSC. Here, we summarize the studies on the stability of PSC and give some perspectives to address this important issues.
Photonics 02 01139 g002 1024
Figure 2. The number of papers published with a topic pertaining to perovskite solar cell. The data presented here were based on Web of Science.
Figure 2. The number of papers published with a topic pertaining to perovskite solar cell. The data presented here were based on Web of Science.
Photonics 02 01139 g002

2. Air (H2O and O2) Stability

A typical perovskite crystalline shows cubic structure with a formula ABX3 (A = organic cation, B = Pb2+ or Sn2+, X = halogen anion) (Figure 3) [11]. The formability and distortion of crystal can be estimated by Goldschmidt’s tolerance factor: t = (rA + rX)/[21/2(rB + rX)], in which rA, rB, rX are the ionic radii of A, B and X ions, respectively [12]. An ideal cubic perovskite crystal is expected for t = 1, while octahedral distortion is achieved for t < 1 [13]. The lattice parameter can be changed by turning halogen anions. For example, the replacement of I− by Br− in tetragonal MAPbI3 leads to the decrease of lattice parameter. As a result, the cubic MAPbBr3 shows more stability than the distorted MAPbI3.
Photonics 02 01139 g003 1024
Figure 3. The structure of organic-lead trihalide perovskite ABX3. Reprinted with permission from the reference [11].
Figure 3. The structure of organic-lead trihalide perovskite ABX3. Reprinted with permission from the reference [11].
Photonics 02 01139 g003
Two components in ambient air, H2O and O2, will affect the chemical stability of PSCs, accompanied by the degradation of perovskite with the color changing from dark brown to yellow. Thus far, there have been few reports focusing on the influence of H2O and O2. In order to achieve a highly stable device, the degradation mechanism of perovskite materials should be investigated. The degradation mechanism of perovskite materials in water condition was studied by Wang et al. [14]. The hydrolysis reaction of MAPbI3 occurs when the material is exposed to the humid condition. At first, the MAPbI3 degrades into PbI2 and MAI in presence of H2O, where MAI further decomposes into CH3NH2 (aq) and HI (aq). Aqueous HI can react with O2 to form I2 (s) and H2O (l) or decompose into H2 (g) and I2 (s). The consumption of HI drives the whole decomposition process and causes the decrease in efficiency of PSC. Frost et al. proposed two reversible reactions, where combination of H2O and nMAPbI3 leads to the formation of CH3NH2 and [(CH3NH3+)n−1(CH3NH2)nPbI3][H2O] and the latter further degrades into the [(CH3NH3+)Pb3]n−1, HI, PbI2 and H2O [15]. Both CH3NH2 and HI exist in gas state at room temperature, which can easily drive the degradation further in a non-encapsulated device [15]. Snaith et al. speculated that the weak hydrogen bonds are formed in crystal structure creating the unbound MAI that can be escaped from the crystal lattice, which eventually leads to the formation of PbI2 [16].
On the premise of decomposition mechanism, different methods are put forward to enhance the stability of PSCs. Wang et al. introduced a thin Al2O3 layer which can protect MAPbI3 film from the water intrusion and is also found to retard the recombination of electrons and holes [14]. After exposing to air for 18 h with a relative humidity of 60% at 35 °C, the Al2O3 modified device maintained 48% of its original efficiency, whereas the device without modification kept only 20% of the original efficiency. Very recently, an ultrathin Al2O3 buffer layer was deposited onto the top of spiro-MeOTAD layer by atomic layer deposition (ALD) [17]. The thickness of Al2O3 layer was precisely controlled by controlling the ALD cycles. The device showed an excellent stability and retained ~90% of its initial PCE in ambient environment for 24 days. The introduction of a hydrophobic buffer layer on the top of perovskite layer is an effective way to enhance the stability of PSC. Snaith et al. used the P3HT/SWNT as HTM instead of spiro-MeOTAD, and a thin PMMA layer was deposited onto the top of P3HT/SWNT layer which greatly enhanced stability to water exposure [16]. The PMMA layer was found to protect the perovskite from water corrosion and MAI evaporation. When tested at 80 °C in air for 96 h, the device showed no significant changes in color, absorbance and crystal structure. Introduction of hydrophobic nature to HTM is one of promising methods. Poly[2,5-bis(2-decyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-(E)-1,2-di(2,20-bithiophen-5-yl) ethene] (PDPPDBTE) was introduced into the PSCs acting as a HTM layer by Kwon et al. [18]. The excellent hydrophobic properties of PDPPDBTE protect MAPbI3 from degradation in moisture condition. The PCE of the PDPPDBTE-based solar cell exhibited a slight decrease, while that of the spiro-MeOTAD-based one declined from 7.6% to 5.5% after 1000 h aging time. Hydrophobicity was related to the water contact angles, where the angles for the P3HT and PDPPDBTE were 105° higher than that for spiro-MeOTAD (70°).
Utilization of highly stable and water-resistant materials is also an effective way to improve the long-term stability of PSC, such as MAPb(I1−xBrx)3 [19], (PEA)2(MA)2[Pb3I10] (PEA = C6H5(CH2)2NH3) [20], and polyaniline [21]. Smaller anion such as Br and larger cation in A-site such as PEA might improve stability of MA cation in the lattice. In addition, surface modification engineering of perovskite also provides an effective method to enhance the stability. Alkylphosphonic acid ω-ammonium chlorides was introduced into the PSCs to modify the surface of MAPbI3, leading to a good stability [22]. Yang’s group found an interesting phenomenon: PSC with a high PCE of 19.3% was achieved in controlled humidity conditions [23]. They argued that the transport of chemicals ions would be accelerated because of dissolution of hygroscopic materials in devices. Very recently, Snaith et al. reported the similar views that moisture exposure in preparation process resulted in the partial solvation of methylammonium component and reorganization of perovskite lattice, leading to a decrease in trap density and an improvement of Voc and photoluminescence [24]. Park et al. reported a water-repellent perovskite based on an anti-reflective lotus leaf-inspired hierarchical pyramidal arrays that were fabricated using polydimethylsiloxane (PDMS) film [25]. The PDMS film adhered to PSC demonstrated excellent super hydrophobicity, which made the PSC water-repellent. Park et al. also proposed crystal chemistry engineering as one of promising methods for stability. Improvement of moisture stability was demonstrated by incorporating Cs ion in FA site of FAPbI3 [26]. Replacement of 10 mol% FA by Cs enhanced stability under 85% relative humidity, which was due to stabilization of FA ion in the contracted lattice induced by smaller Cs ion incorporation.
The degradation mechanism of perovskite in the presence of O2 was studied by Aristidou et al. [27]. Mesoporous (mp)-Al2O3 and mp-TiO2 based PSCs were fabricated and studied in dry O2 without moisture. They found that superoxide O2− is generated when O2 reacts with photo-generated electrons, which leads to the deprotonation of MAPbI3, resulting in decomposition into CH3NH2, PbI2, I2 and H2O. The utilization of TiO2 can help reduce the generation of O2− because of electron injection by TiO2 (Figure 4). It is worth noting that even in dry condition water can be generated in presence of O2 and light, which can further accelerate the degradation of the perovskite.
Photonics 02 01139 g004 1024
Figure 4. Schematic model showing the electron transfer of the photo-excited electrons in the MAPbI3 layer to oxygen resulting in the formation of superoxide. Reprinted with permission from the reference [27].
Figure 4. Schematic model showing the electron transfer of the photo-excited electrons in the MAPbI3 layer to oxygen resulting in the formation of superoxide. Reprinted with permission from the reference [27].
Photonics 02 01139 g004
Yang’s group reported a highly stable PSC in p-i-n structure using inorganic p-type NiOx and n-type ZnO nanoparticles as hole and electron transport material, respectively [28]. The devices maintained ~90% of their initial efficiencies after 60 days at room temperature in ambient air environment. In fact, advanced sealing techniques in industrial production are expected to protect the device effectively, which eventually solve most of the water and O2 induced degradation problems.

3. Thermal Stability

In normal practical condition, direct exposure of PSC to sunlight will increase temperature of solar panel. The accumulation of heat can get a temperature as high as 85 °C assuming that the environmental temperature is 40 °C [29]. There are two kinds of thermal degradation in device: one is the intrinsic thermal instability of the perovskite material itself and another comes from other unstable layers such as HTM. The intrinsic thermal stability of MAPbI3−xClx was studied by Conings et al. and they found that the degradation occurred at 85 °C even in inert condition [30], which means that PSCs may not be widely used in actual daytime if the device temperature exceeds 85 °C. Thus, heat-tolerant perovskite absorbers are necessary for long-term thermal stability of PSCs. Alternatively, the application of high thermal conductive materials is expected to be one of ways to decrease the internal heat accumulation in PSCs. In order to get a better understanding of thermally induced degradation, the formation energy of per unit cell in MAPbI3−xClx crystalline was calculated to be 0.11~0.14 eV [30]. Thermal energy (0.093 eV) calculated at 85 °C is quite close to the formation energy. Thus degradation at 85 °C is expected. Thermogravimetric analysis (TGA) was studied to understand the thermal behavior of MAPbX3 (X = I or Cl) [31], in which the organic component of the perovskite was thermally decomposed to HI and CH3NH2 leading to a subsequent degradation. Pisoni et al. studied the thermal conductive properties of MAPbI3 [32]. Their research showed that thermal conductivity of MAPbX3 was very low in both single crystals and polycrystals. The heat inside the perovskite could not spread out quickly, which caused the mechanical stress and limited the lifetime of the PSCs [32].
Misra et al. proposed an acceleration test for degradation of MAPbX3 (X = I or Br) [33]. Encapsulated MAPbX3 based devices were fabricated and measured under 100 suns illumination for 1 h with different internal temperature (25 °C and ~50 °C, respectively). The thermal stability was better for the MAPbBr3 based device than for the MAPbI3 based one. A mixed hailed MAPbI3−xBrx with large bandgap was suggested for thermally stable and highly efficient PSC [33]. Snaith et al. reported the PSC based on FAPbI3 with high thermal stability [34], where the substrates of FAPbI3 and MAPbI3 were prepared and heated in air at 150 °C. The former showed a higher stability without bleaching for 60 min while the latter was bleached after 30 min. The promising stability of FAPbI3 provides a new direction toward long-term thermal stability.
Malinauskas et al. argued that the fully symmetrical spiro-MeOTAD tends to be easily crystallized, which can affect the contact between the perovskite and the HTM [35]. Local asymmetry was introduced into the spiro-MeOTAD to suppress the crystal growth. Based on the modified HTM, the device demonstrated that ~90% of its initial efficiency was maintained after 1000 h at 60 °C. Abate et al. also found that the HTM has a dramatic influence on the stability of the device [36]. Thermally stable silolothiophene-linked triphenylamines (Si-MeOTAD) was proposed as a new HTM, which showed six times higher half-life than the spiro-MeOTAD based device. HTM-free PSCs will be one of methods to solve the thermal instability. Han’s group fabricated a mesoscopic TiO2/ZrO2/MAPbI3 solar cell with carbon black/spheroidal graphite electrode like monolithic DSSC [37]. In their subsequent work, Li et al. prepared a HTM-free PSC and investigated its stability in real conditions [38]. The device with carbon electrode demonstrated an excellent stability and maintained the initial efficiency for three months at 80~85 °C. Wei et al. utilized a multifunctional carbon with epoxy/Ag-paint as a cathode layer, which showed little degradation when exposing the device to high temperature or moisture [39]. A reasonable speculation was proposed that the absence of HTM and the utilization of thermally conductive carbon materials can help dissipate the internal heat of the device. Therefore, transferring the internal heat to outside of device will be an effective way to solve the thermal instability of MAPbI3 material and device, using materials with high heat transmission coefficient such as graphene [40,41].

4. Photo Stability

A mesoporous TiO2 layer in the mesoscopic device structure was used to transport photo-generated electrons. However, TiO2 is an important semiconductor for photocatalysis [42] and is sensitive to ultraviolet (UV) light. Snaith et al. studied photoinduced instability of PSCs and found that performance of the encapsulated device degraded faster than that of the unpacked device (Figure 5a) [43]. However, the encapsulated device was more stable in the absence of UV irradiation. In order to explain this phenomenon, they put forward the degradation mechanism (see Figure 5b). Electron-hole pair is formed in TiO2 nanoparticle in presence of UV light. The hole in valence band recombines with the electron at the O2 adsorption site by desorbing O2. The electrons generated in light absorbers are injected either into the conduction band of TiO2 or into the deep surface traps [43]. The free electrons left in the TiO2 recombine with the holes generated from spiro-MeOTAD. Based on this hypothesis, mesoporous Al2O3 was introduced into PSC instead of the TiO2 nanoparticles achieving a long-term stability over 1000 h at 40 °C. However, the performance of device suffered from a continue decrease in both Voc and FF over the first 200 h with the PCE decreasing to ~50% of its initial value [43].
Photonics 02 01139 g005 1024
Figure 5. (a) The evolution of performance parameters measured in different conditions and (b) degradation mechanism against UV light. Reprinted with permission from reference [43].
Figure 5. (a) The evolution of performance parameters measured in different conditions and (b) degradation mechanism against UV light. Reprinted with permission from reference [43].
Photonics 02 01139 g005
Photoinduced stability of FAPbI3 was also studied by Park’s group [9]. Current-voltage curves for the PSCs based on the FAPbI3 and MAPbI3 were repeatedly measured under one sun illumination. The FAPbI3 based device showed a better stability than the MAPbI3 based one, which indicates that the photo-stability of FAPbI3 provides a new direction to enhance the stability and improve the performance of solar cells.

5. Effect of Additives in HTM on Stability

Spiro-MeOTAD is the common HTM used in PSC, where two typical additives of 4-tert-butylpyridine (TBP) and bis(trifluoromethane)sulfonamide lithium salt (Li-TFSI) are used in general. The utilization of TBP can increase the polarity of HTM and enhance the interfacial contact between perovskite and HTM, leading to a high Voc and PCE [44]. Unfortunately, the polarity of TBP make it possible to dissolve perovskite materials which means that perovskite can be corroded by TBP [44]. At the same time, the addition of Li-TFSI is known to promote the oxidation of spiro-MeOTAD in order to increase the hole mobility and conductivity. However, the oxidation process may have a negative effect on the stability of PSC as we discussed previously. Introducing a buffer layer at the perovskite/HTM interface or developing new HTMs without caustic additives can keep perovskite from corrosion and maintain the long-term instability.
The instability of perovskite due to corrosion by TBP was studied by Li et al. [44]. It was found that PbI2 can be dissolved in TBP solution, resulting in a yellow liquid solution. Based on the UV-vis spectra and XPS results, they put forward a degradation mechanism as follows:
MAPbI3(s) ⇌ MAI(s) + PbI2(s)
PbI2(s) + xTBP (s) → PbI2 − TBPx (aq)
PbI2(s) + xTBP (s) → [PbI2·xTBP] (s)
The degradation of the MAPbI3 leads to the formation of MAI and PbI2 in Reaction (1). PbI2 can react with TBP to form a complex in both Reactions (2) and (3), which promotes the decomposition of perovskite. They used montmorillonite as a buffer layer between perovskite layer and HTM to protect perovskite from erosion and increase the lifetime of the device [44]. Modified Al2O3 layer is likely to be an effective material for protecting perovskite film from the corrosion by additive [27].
Developing new non-corrosive HTM is also a good way to protect the perovskite from erosion by additives in spiro-MeOTAD. Poly[N-9-hepta-decanyl-2,7-carbazole-alt-3,6-bis-(thiophen-5-yl)-2,5-dioctyl-2,5-di-hydropyrrolo[3,4-]pyrrole-1,4-dione] (PCBTDPP) was fabricated and used as HTM in PSCs by Cai et al. [45]. The device shows a superior stability with a peak efficiency of 5.55% after stored in air at room temperature for 576 h. Liu et al. introduced a new additive-free HTM, tetrathiafulvalene derivative (TTF-1), into the PSCs [46]. The TTF-1 based device without additives showed a slower degradation rate compared to the device with the additive contained spiro-MeOTAD and maintained ~80% of its initial PCE for 500 h under a relative humidity of ~40%. Other HTMs were also fabricated and used in PSCs, such as amine derivatives [47], oligothiophene derivative [48], and MoO3/PEDOT:PSS [49]. These HTMs were proposed as potential candidates for long-term stable materials for PSCs.

6. Summary and Perspective

Despite the relatively high performance of PCSs, the current conditions still do not meet the requirement for commercialization. There are three main stability issues in PSCs, which are air (moisture and oxygen) stability, photo stability and thermal stability. In addition, selective contacts and additives in HTM can also have influence on stability. Introduction of a condense buffer layer into the structure is an effective way to protect perovskite from corrosion by moisture or O2 or additives. Thus far, the poor photo stability of the devices mainly stems from the unstable property of TiO2 nanoparticles. Seeking a proper electron transport material to replace TiO2 might be the key to solving this problem. Thermal stability of perovskite is the most important issue. To solve this problem, a fast dissipation of internal heat in device is expected to be one of good ways to get rid of thermal instability. Design and fabrication of new thermal-tolerant perovskite absorber are regarded as a possible method to solve thermal instability problem. For example, a two-inch-sized perovskite crystal was synthesized by Liu et al. [50]. The crystal shows an excellent thermal stability with a high decomposition temperature at 270 °C. Further investigations on factors affecting stability of PSCs more in detail, along with effective ways to solve instability, are required to launch PSCs in the market.

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Ministry of Science, ICT & Future Planning (MSIP) of Korea under contracts No. NRF-2012M3A6A7054861 (Global Frontier R & D Program on Center for Multiscale Energy System) and 2012M3A7B4049986 (Nano Material Technology Development Program).

Conflict of Interest

The authors declare no conflict of interest.

References

  1. Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. J. Am. Chem. Soc. 2009, 131, 6050–6051. [Google Scholar] [CrossRef] [PubMed]
  2. Im, J.-H.; Lee, C.-R.; Lee, J.-W.; Park, S.-W.; Park, N.-G. 6.5% efficient perovskite quantum-dot-sensitized solar cell. Nanoscale 2011, 3, 4088–4093. [Google Scholar] [CrossRef] [PubMed]
  3. O’Regan, B.; Grätzel, M. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 1991, 353, 737–740. [Google Scholar] [CrossRef]
  4. Kim, H.-S.; Lee, C.-R.; Im, J.-H.; Lee, K.-B.; Moehl, T.; Marchioro, A.; Moon, S.-J.; Humphry-Baker, R.; Yum, J.-H.; Moser, J.E.; et al. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Sci. Rep. 2012, 2, 1–7. [Google Scholar] [CrossRef] [PubMed]
  5. Bach, U.; Lupo, D.; Comte, P.; Moser, J.E.; Weissörtel, F.; Salbeck, J.; Spreitzer, H.; Grätzel, M. Solid-state dye-sensitized mesoporous TiO2 solar cells with high photon-to-electron conversion efficiencies. Nature 1998, 395, 583–585. [Google Scholar] [CrossRef]
  6. Lee, M.M.; Teuscher, J.; Miyasaka, T.; Murakami, T.N.; Snaith, H.J. Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 2012, 338, 643–647. [Google Scholar] [CrossRef] [PubMed]
  7. Burschka, J.; Pellet, N.; Moon, S.J.; Humphry-Baker, R.; Gao, P.; Nazeeruddin, M.K.; Grätzel, M. Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature 2013, 499, 316–319. [Google Scholar] [CrossRef] [PubMed]
  8. Liu, M.Z.; Johnston, M.B.; Snaith, H.J. Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature 2013, 501, 395–398. [Google Scholar] [CrossRef] [PubMed]
  9. Lee, J.-W.; Seol, D.-J.; Cho, A.-N.; Park, N.-G. High-efficiency perovskite solar cells based on the black polymorph of HC(NH2)2PbI3. Adv. Mater. 2014, 26, 4991–4998. [Google Scholar] [CrossRef] [PubMed]
  10. Yang, W.-S.; Noh, J.-H.; Jeon, N.-J.; Kim, Y.-C.; Ryu, S.; Seo, J.; Seok, S.I. High-performance photovoltaic perovskite layers fabricated through intramolecular exchange. Science 2015, 348, 1234–1237. [Google Scholar] [CrossRef] [PubMed]
  11. Park, N.-G. Perovskite solar cells: An emerging photovoltaic technology. Mater. Today 2015, 18, 65–72. [Google Scholar] [CrossRef]
  12. Goldschmidt, V.M. Die gesetze der krystallochemie. Naturwissenschaften 1926, 14, 477–485. [Google Scholar] [CrossRef]
  13. Rini, M.; Tobey, R.; Dean, N.; Itatani, J.; Tomioka, Y.; Tokura, Y.; Schoenlein, R.W.; Cavalleri, A. Control of the electronic phase of a manganite by mode-selective vibrational excitation. Nature 2007, 449, 72–74. [Google Scholar] [CrossRef] [PubMed]
  14. Niu, G.D.; Li, W.Z.; Meng, F.Q.; Wang, L.D.; Dong, H.P.; Qiu, Y. Study on the stability of CH3NH3PbI3 films and the effect of post-modification by aluminum oxide in all-solid-state hybrid solar cells. J. Mater. Chem. A 2014, 2, 705–710. [Google Scholar] [CrossRef]
  15. Frost, J.M.; Butler, K.T.; Brivio, F.; Hendon, C.H.; van Schilfgaarde, M.; Walsh, A. Atomistic origins of high-performance in hybrid halide perovskite solar cells. Nano Lett. 2014, 14, 2584–2590. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  16. Habisreutinger, S.N.; Leijtens, T.; Eperon, G.E.; Stranks, S.D.; Nicholas, R.J.; Snaith, H.J. Carbon nanotube/polymer composites as a highly stable hole collection layer in perovskite solar cells. Nano Lett. 2014, 14, 5561–5568. [Google Scholar] [CrossRef] [PubMed]
  17. Dong, X.; Fang, X.; Lv, M.H.; Lin, B.C.; Zhang, S.; Ding, J.N.; Yuan, N.Y. Improvement of the humidity stability of organic-inorganic perovskite solar cells using ultrathin Al2O3 layers prepared by atomic layer deposition. J. Mater. Chem. A 2015, 3, 5360–5367. [Google Scholar] [CrossRef]
  18. Kwon, Y.S.; Lim, J.; Yun, H.-J.; Kim, Y.-H.; Park, T. A diketopyrrolopyrrole-containing hole transporting conjugated polymer for use in efficient stable organic-inorganic hybrid solar cells based on a perovskite. Energy Environ. Sci. 2014, 7, 1454–1460. [Google Scholar] [CrossRef]
  19. Noh, J.-H.; Im, S.-H.; Heo, J.-H.; Mandal, T.N.; Seok, S.-I. Chemical management for colorful, efficient, and stable inorganic-organic hybrid nanostructured solar cells. Nano Lett. 2013, 13, 1764–1769. [Google Scholar] [CrossRef] [PubMed]
  20. Smith, I.C.; Hoke, E.T.; Solis-Ibarra, D.; McGehee, M.D.; Karunadasa, H.I. A layered hybrid perovskite solar-cell absorber with enhanced moisture stability. Angew. Chem. Int. Ed. 2014, 53, 1–5. [Google Scholar] [CrossRef] [PubMed]
  21. Xiao, Y.M.; Han, G.Y.; Chang, Y.Z.; Zhou, H.H.; Li, M.Y.; Li, Y.P. An all-solid-state perovskite-sensitized solar cell based on the dual function polyaniline as the sensitizer and p-type hole-transporting material. J. Power Sources 2014, 267, 1–8. [Google Scholar] [CrossRef]
  22. Li, X.; Dar, M.I.; Yi, C.Y.; Luo, J.S.; Tschumi, M.; Zakeeruddin, S.M.; Nazeeruddin, M.K.; Han, H.W.; Grätzel, M. Improved performance and stability of perovskite solar cells by crystal crosslinking with alkylphosphonic acid ω-ammonium chlorides. Nat. Chem. 2015, 7, 703–711. [Google Scholar] [CrossRef] [PubMed]
  23. Zhou, H.P.; Chen, Q.; Li, G.; Luo, S.; Song, T.B.; Duan, H.S.; Hong, Z.R.; You, J.B.; Liu, Y.S.; Yang, Y. Interface engineering of highly efficient perovskite solar cells. Science 2014, 345, 542–546. [Google Scholar] [CrossRef] [PubMed]
  24. Eperon, G.E.; Habisreutinger, S.N.; Leijtens, T.; Bruijnaers, B.J.; Franeker, J.J.; DeQuilettes, D.W.; Pathak, S.; Sutton, R.J.; Grancini, G.; Ginger, D.S.; et al. The importance of moisture in hybrid lead halide perovskite thin film fabrication. ACS Nano 2015, 9, 9380–9393. [Google Scholar] [CrossRef] [PubMed]
  25. Kang, S.M.; Ahn, N.; Lee, J.-W.; Choi, M.; Park, N.-G. Water-repellent perovskite solar cell. J. Mater. Chem. A 2014, 2, 20017–20021. [Google Scholar] [CrossRef]
  26. Lee, J.-W.; Kim, D.-H.; Kim, H.-S.; Seo, S.-S.; Cho, S.-M.; Park, N.-G. Formamidinium and cesium hybridization for photo- and moisture-stable perovskite solar cell. Adv. Energy Mater. 2015, 5. [Google Scholar] [CrossRef]
  27. Aristidou, N.; Sanchez-Molina, I.; Chotchuangchutchaval, T.; Brown, M.; Martinez, L.; Rath, T.; Haque, S.A. The role of oxygen in the degradation of methylammonium lead trihalide perovskite photoactive layers. Angew. Chem. Int. Ed. 2015, 54, 8208–8212. [Google Scholar] [CrossRef] [PubMed]
  28. You, J.B.; Meng, L.; Song, T.-B.; Guo, T.-F.; Yang, Y.; Chang, W.-H.; Hong, Z.R.; Chen, H.J.; Zhou, H.P.; Chen, Q.; et al. Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers. Nature Nanotech. 2015. [Google Scholar] [CrossRef] [PubMed]
  29. Cuddihy, E.; Coulbert, C.; Gupta, A.; Liang, R. Flat-plate Solar Array Project Final Report; JPL Publication: Springfield, VA, USA, 1986; Volume VII, pp. 86–31. [Google Scholar]
  30. Conings, B.; Drijkoningen, J.; Gauquelin, N.; Babayigit, A.; D’Haen, J.; D’Olieslaeger, L.; Ethirajan, A.; Verbeeck, J.; Manca, J.; Mosconi, E.; et al. Intrinsic thermal instability of methylammonium lead trihalide perovskite. Adv. Energy Mater. 2015, 5. [Google Scholar] [CrossRef]
  31. Dualeh, A.; Gao, P.; Seok, S.I.; Nazeeruddin, M.K.; Gräetzel, M. Thermal behavior of methylammonium lead-trihalide perovskite photovoltaic light harvesters. Chem. Mater. 2014, 26, 6160–6164. [Google Scholar] [CrossRef]
  32. Pisoni, A.; Jaćimović, J.; Barišić, O.S.; Spina, M.; Gaál, R.; Forró, L.; Horváth, E. Ultra-low thermal conductivity in organic-inorganic hybrid perovskite CH3NH3PbI3. J. Phys. Chem. Lett. 2014, 5, 2488–2492. [Google Scholar] [CrossRef] [PubMed]
  33. Misra, R.K.; Aharon, S.; Li, B.; Mogilyansky, D.; Visoly-Fisher, I.; Etgar, L.; Katz, E.A. Temperature- and component-dependent degradation of perovskite photovoltaic materials under concentrated sunlight. J. Phys. Chem. Lett. 2015, 6, 326–330. [Google Scholar] [CrossRef] [PubMed]
  34. Eperon, G.E.; Stranks, S.D.; Menelaou, C.; Johnston, M.B.; Herz, L.M.; Snaith, H.J. Formamidinium lead trihalide: A broadly tunable perovskite for efficient planar heterojunction solar cells. Energy Environ. Sci. 2014, 7, 982–988. [Google Scholar] [CrossRef]
  35. Malinauskas, T.; Tomkute-Luksiene, D.; Sens, R.; Daskeviciene, M.; Send, R.; Wonneberger, H.; Jankauskas, V.; Bruder, I.; Getautis, V. Enhancing thermal stability and lifetime of solid-state dye-sensitized solar cells via molecular engineering of the hole-transporting material spiro-OMeTAD. ACS Appl. Mater. Interfaces 2015, 7, 11107–11116. [Google Scholar] [CrossRef] [PubMed]
  36. Abate, A.; Paek, S.; Giordano, F.; Correa-Baena, J.-P.; Saliba, M.; Gao, P.; Matsui, T.; Ko, J.; Zakeeruddin, S.M.; Dahmen, K.H.; et al. Silolothiophene-linked triphenylamines as stable hole transporting materials for high efficiency perovskite solar cells. Energy Environ. Sci. 2015, 8, 2946–2953. [Google Scholar] [CrossRef]
  37. Ku, Z.L.; Rong, Y.G.; Xu, M.; Liu, T.F.; Han, H.W. Full printable processed mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cells with carbon counter electrode. Sci. Rep. 2013, 3, 1–5. [Google Scholar] [CrossRef] [PubMed]
  38. Li, X.; Tschumi, M.; Han, H.W.; Babkair, S.S.; Alzubaydi, R.A.; Ansari, A.A.; Habib, S.S.; Nazeeruddin, M.K.; Zakeeruddin, S.M.; Grätzel, M. Outdoor performance and stability under elevated temperatures and long-term light soaking of triple-layer mesoporous perovskite photovoltaics. Energy Technol. 2015, 3, 551–555. [Google Scholar] [CrossRef]
  39. Wei, Z.; Zheng, X.; Chen, H.; Long, X.; Wang, Z.; Yang, S. A multifunctional C plus epoxy/Ag-paint cathode enables efficient and stable operation of perovskite solar cells in watery environments. J. Mater. Chem. A 2015, 3, 16430–16434. [Google Scholar] [CrossRef]
  40. Luo, Q.; Zhang, Y.; Liu, C.Y.; Li, J.B.; Wang, N.; Lin, H. Iodide-reduced graphene oxide with dopant-free spiro-OMeTAD for ambient stable and high-efficiency perovskite solar cells. J. Mater. Chem. A 2015, 3, 15996–16004. [Google Scholar] [CrossRef]
  41. Yeo, J.-S.; Kang, R.; Lee, S.; Jeon, Y.-J.; Myoung, N.; Lee, C.-L.; Kim, D.-Y.; Yun, J.-M.; Seo, Y.-H.; Kim, S.-S.; et al. Highly efficient and stable planar perovskite solar cells with reduced graphene oxide nanosheets as electrode interlayer. Nano Energy 2015, 12, 96–104. [Google Scholar] [CrossRef]
  42. Mills, A.; Hunte, S.L. An overview of semiconductor photocatalysis. J. Photochem. Photobiol. A Chem. 1997, 108, 1–35. [Google Scholar] [CrossRef]
  43. Leijtens, T.; Eperon, G.E.; Pathak, S.; Abate, A.; Lee, M.M.; Snaith, H.J. Overcoming ultraviolet light instability of sensitized TiO2 with meso-superstructured organometal tri-halide perovskite solar cells. Nat. Commun. 2013, 4, 1–8. [Google Scholar] [CrossRef] [PubMed]
  44. Li, W.Z.; Dong, H.P.; Wang, L.D.; Li, N.; Guo, X.D.; Li, J.W.; Qiu, Y. Montmorillonite as bifunctional buffer layer material for hybrid perovskite solar cells with protection from corrosion and retarding recombination. J. Mater. Chem. A 2014, 2, 13587–13592. [Google Scholar] [CrossRef]
  45. Cai, B.; Xing, Y.D.; Yang, Z.; Zhang, W.H.; Qiu, J.S. High performance hybrid solar cells sensitized by organolead halide perovskites. Energy Environ. Sci. 2013, 6, 1480–1485. [Google Scholar] [CrossRef]
  46. Liu, J.; Wu, Y.Z.; Qin, C.J.; Yang, X.D.; Yasuda, T.; Islam, A.; Zhang, K.; Peng, W.Q.; Chen, W.; Han, L.Y. A dopant-free hole-transporting material for efficient and stable perovskite solar cells. Energy Environ. Sci. 2014, 7, 2963–2967. [Google Scholar] [CrossRef]
  47. Choi, H.; Paek, S.; Lim, N.; Lee, Y.H.; Nazeeruddin, M.K.; Ko, J. Efficient perovskite solar cells with 13.63% efficiency based on planar triphenylamine hole conductors. Chem. Eur. J. 2014, 20, 10894–10899. [Google Scholar] [CrossRef] [PubMed]
  48. Zheng, L.L.; Chung, Y.-H.; Ma, Y.Z.; Zhang, L.P.; Xiao, L.X.; Chen, Z.J.; Wang, S.F.; Qu, B.; Gong, Q.H. A hydrophobic hole transporting oligothiophene for planar perovskite solar cells with improved stability. Chem. Commun. 2014, 50, 11196–11199. [Google Scholar] [CrossRef] [PubMed]
  49. Hou, F.H.; Su, Z.S.; Jin, F.M.; Yan, X.W.; Wang, L.D.; Zhao, H.F.; Zhu, J.Z.; Chu, B.; Li, W.L. Efficient and stable planar heterojunction perovskite solar cells with an MoO3/PEDOT: PSS hole transporting layer. Nanoscale 2015, 7, 9427–9432. [Google Scholar] [CrossRef] [PubMed]
  50. Liu, Y.C.; Yang, Z.; Cui, D.; Ren, X.D.; Sun, J.K.; Liu, X.J.; Zhang, J.R.; Wei, Q.B.; Fan, H.B.; Yu, F.Y.; et al. Two-inch-sized perovskite CH3NH3PbX3 (X = Cl, Br, I) crystals: Growth and characterization. Adv. Mater. 2015, 27, 5176–5183. [Google Scholar] [CrossRef] [PubMed]

Share and Cite

MDPI and ACS Style

Zhao, X.; Park, N.-G. Stability Issues on Perovskite Solar Cells. Photonics 2015, 2, 1139-1151. https://doi.org/10.3390/photonics2041139

AMA Style

Zhao X, Park N-G. Stability Issues on Perovskite Solar Cells. Photonics. 2015; 2(4):1139-1151. https://doi.org/10.3390/photonics2041139

Chicago/Turabian Style

Zhao, Xing, and Nam-Gyu Park. 2015. "Stability Issues on Perovskite Solar Cells" Photonics 2, no. 4: 1139-1151. https://doi.org/10.3390/photonics2041139

APA Style

Zhao, X., & Park, N. -G. (2015). Stability Issues on Perovskite Solar Cells. Photonics, 2(4), 1139-1151. https://doi.org/10.3390/photonics2041139

Article Metrics

Back to TopTop