Solution-Processed Metal Oxide Nanostructures for Carrier Transport

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Nanophotonics Materials and Devices".

Deadline for manuscript submissions: closed (31 August 2022) | Viewed by 15582

Special Issue Editor


E-Mail Website
Guest Editor
Institute of Lighting and Energy Photonics, College of Photonics, National Yang Ming Chiao Tung University (NYCU), Tainan 71150, Taiwan
Interests: ionic conjugated polymers; metal oxide thin films, nanoparticles, and nanorod arrays; perovskite materials; organic light-emitting diodes (OLEDs); polymer solar cells; quantum-dot light-emitting diodes (QLEDs); perovskite solar cells (PSCs) and light-emitting diodes (PeLEDs)
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Metal oxide semiconductors represent a unique class of materials that show prominent optoelectronic applications today. Typical p-type metal oxides, such as vanadium oxide (VOx), nickel oxide (NiOx), and cobalt oxide (CoOx), have the advantages of high hole mobility, superior stability, and solution processibility. On the other hand, several representative n-type metal oxide materials, including zinc oxide (ZnO), titanium dioxide (TiO2), and tin dioxide (SnO2), show benefits in device performance due to their high electron mobility, long-term stability, solution-processing capability, and relatively high abundance on earth. In addition to thin films, metal oxides with specific nanostructures such as nanoparticles, nanowires, nanorods, nanotubes, nanosheets, nanowalls, and nanoflowers, have also been developed to increase the active surface area. These nanostructures are achievable via solution processes to reduce production cost and to expand research diversity. Nanostructured metal oxides are especially useful for carrier transport in miscellaneous devices, including organic light emitting diodes, polymer solar cells, perovskite photovoltaics, perovskite light emitting diodes, quantum-dot light emitting diodes, and organic/inorganic hybrid transistors and sensors.

This Special Issue of Nanomaterials is open to manuscripts concerning synthesis, characterization, and especially carrier transport abilities of metal oxide thin films and nanostructures in working devices. Potential topics include but are not limited to:

  • Hole transport metal oxides such as VOx, NiOx, CoOx, etc.;
  • Electron transport metal oxides such as ZnO, TiO2, SnO2, etc.;
  • Preparation and characterization of metal oxide thin films and nanostructures;
  • Utilization of nanostructured metal oxides as carrier transport layers in miscellaneous devices.

Dr. Sheng-Hsiung Yang
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • metal oxide semiconductors
  • solution processibility
  • nanostructures
  • organic optoelectronics
  • perovskite photovoltaics and light-emitting diodes
  • quantum-dot light-emitting diodes
  • transistors and sensors

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research

3 pages, 176 KiB  
Editorial
Solution-Processed Metal Oxide Nanostructures for Carrier Transport
by Sheng-Hsiung Yang
Nanomaterials 2023, 13(8), 1331; https://doi.org/10.3390/nano13081331 - 11 Apr 2023
Cited by 2 | Viewed by 1235
Abstract
Metal oxide semiconductors represent a unique class of materials that show prominent optoelectronic applications nowadays [...] Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)

Research

Jump to: Editorial

14 pages, 2626 KiB  
Article
Organic–Inorganic Hybrid Device with a Novel Deep-Blue Emitter of a Donor–Acceptor Type, with ZnO Nanoparticles for Solution-Processed OLEDs
by Seokwoo Kang, Raveendra Jillella, Sunwoo Park, Sangshin Park, Joo Hwan Kim, Dakyeung Oh, Joonghan Kim and Jongwook Park
Nanomaterials 2022, 12(21), 3806; https://doi.org/10.3390/nano12213806 - 28 Oct 2022
Cited by 2 | Viewed by 2190
Abstract
Two new deep-blue emitters with bipolar properties based on an organoboron acceptor and carbazole donor were newly synthesized: 2-(9H-carbazol-9-yl)-5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-5H-benzo[b]carbazole (TDBA-BCZ) and 5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-8-phenyl-5,8-dihydroindolo[2,3-c]carbazole (TDBA-PCZ). The two emitters showed deep-blue and real-blue photoluminescence emission in their solution and film states, respectively. The doped [...] Read more.
Two new deep-blue emitters with bipolar properties based on an organoboron acceptor and carbazole donor were newly synthesized: 2-(9H-carbazol-9-yl)-5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-5H-benzo[b]carbazole (TDBA-BCZ) and 5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-8-phenyl-5,8-dihydroindolo[2,3-c]carbazole (TDBA-PCZ). The two emitters showed deep-blue and real-blue photoluminescence emission in their solution and film states, respectively. The doped spin-coated films were prepared using synthesized materials and showed a root-mean-square roughness of less than 0.52 nm, indicating excellent surface morphology. The doped devices, fabricated via a solution process using TDBA-BCZ and TDBA-PCZ as the dopants, showed electroluminescence peaks at 428 and 461 nm, corresponding to the Commission Internationale de L’éclairage (CIE) coordinates of (0.161, 0.046) and (0.151, 0.155), respectively. The external quantum efficiency (EQE)/current efficiency (CE) of the solution-processed forward devices, with TDBA-BCZ and TDBA-PCZ as dopants, were 7.73%/8.67 cd/A and 10.58%/14.24 cd/A, respectively. An inverted OLED device fabricated using rod-shaped ZnO nanoparticles as an electron injection layer showed a CE of 1.09 cd/A and an EQE of 0.30%. Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)
Show Figures

Figure 1

15 pages, 5671 KiB  
Article
Preparation of Nickel Oxide Nanoflakes for Carrier Extraction and Transport in Perovskite Solar Cells
by Chih-Yu Chang, You-Wei Wu, Sheng-Hsiung Yang and Ibrahim Abdulhalim
Nanomaterials 2022, 12(19), 3336; https://doi.org/10.3390/nano12193336 - 25 Sep 2022
Cited by 3 | Viewed by 2399
Abstract
Hole transport layers (HTLs) with high conductivity, charge extraction ability, and carrier transport capability are highly important for fabricating perovskite solar cells (PSCs) with high power conversion efficiency and device stability. Low interfacial recombination between the HTL and perovskite absorber is also crucial [...] Read more.
Hole transport layers (HTLs) with high conductivity, charge extraction ability, and carrier transport capability are highly important for fabricating perovskite solar cells (PSCs) with high power conversion efficiency and device stability. Low interfacial recombination between the HTL and perovskite absorber is also crucial to the device performance of PSCs. In this work, we developed a three-stage method to prepare NiOx nanoflakes as the HTL in the inverted PSCs. Due to the addition of the nanoflake layer, the deposited perovskite films with larger grain sizes and fewer boundaries were obtained, implying higher photogenerated current and fill factors in our PSCs. Meanwhile, the downshifted valence band of the NiOx HTL improved hole extraction from the perovskite absorber and open-circuit voltages of PSCs. The optimized device based on the NiOx nanoflakes showed the highest efficiency of 14.21% and a small hysteresis, which outperformed the NiOx thin film as the HTL. Furthermore, the device maintained 83% of its initial efficiency after 60 days of storage. Our results suggest that NiOx nanoflakes provide great potential for constructing PSCs with high efficiency and long-term stability. Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)
Show Figures

Figure 1

21 pages, 11139 KiB  
Article
Enhanced Luminance of CdSe/ZnS Quantum Dots Light-Emitting Diodes Using ZnO-Oleic Acid/ZnO Quantum Dots Double Electron Transport Layer
by Da Young Lee, Hong Hee Kim, Ji-Hyun Noh, Keun-Yong Lim, Donghee Park, In-Hwan Lee and Won Kook Choi
Nanomaterials 2022, 12(12), 2038; https://doi.org/10.3390/nano12122038 - 14 Jun 2022
Cited by 3 | Viewed by 2771
Abstract
The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between [...] Read more.
The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between the valence band (VB) (6.38 eV) of ZnO ETL and (6.3 eV) of CdSe/ZnS QDs. In this study, ZnO QDs chemically reacted with capping ligands of oleic acid (OA) to decrease the work function of 3.15 eV for ZnO QDs to 2.72~3.08 eV for the ZnO-OA QDs due to the charge transfer from ZnO to OA ligands and improve the efficiency for hole blocking as the VB was increased up to 7.22~7.23 eV. Compared to the QLEDs with a single ZnO QDs ETL, the ZnO-OA/ZnO QDs double ETLs optimize the energy level alignment between ZnO QDs and CdSe/ZnS QDs but also make the surface roughness of ZnO QDs smoother. The optimized glass/ITO/PEDOT:PSS/PVK//CdSe/ZnS//ZnO-OA/ZnO/Ag QLEDs enhances the maximum luminance by 5~9% and current efficiency by 16~35% over the QLEDs with a single ZnO QDs ETL, which can be explained in terms of trap-charge limited current (TCLC) and the Fowler-Nordheim (F-N) tunneling conduction mechanism. Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)
Show Figures

Figure 1

17 pages, 7735 KiB  
Article
A Morphological Study of Solvothermally Grown SnO2 Nanostructures for Application in Perovskite Solar Cells
by Zhuldyz Yelzhanova, Gaukhar Nigmetova, Damir Aidarkhanov, Bayan Daniyar, Bakhytzhan Baptayev, Mannix P. Balanay, Askhat N. Jumabekov and Annie Ng
Nanomaterials 2022, 12(10), 1686; https://doi.org/10.3390/nano12101686 - 15 May 2022
Cited by 11 | Viewed by 3192
Abstract
Tin(IV) oxide (SnO2) nanostructures, which possess larger surface areas for transporting electron carriers, have been used as an electron transport layer (ETL) in perovskite solar cells (PSCs). However, the reported power conversion efficiencies (PCEs) of this type of PSCs show a [...] Read more.
Tin(IV) oxide (SnO2) nanostructures, which possess larger surface areas for transporting electron carriers, have been used as an electron transport layer (ETL) in perovskite solar cells (PSCs). However, the reported power conversion efficiencies (PCEs) of this type of PSCs show a large variation. One of the possible reasons for this phenomenon is the low reproducibility of SnO2 nanostructures if they are prepared by different research groups using various growth methods. This work focuses on the morphological study of SnO2 nanostructures grown by a solvothermal method. The growth parameters including growth pressure, substrate orientation, DI water-to-ethanol ratios, types of seed layer, amount of acetic acid, and growth time have been systematically varied. The SnO2 nanomorphology exhibits a different degree of sensitivity and trends towards each growth factor. A surface treatment is also required for solvothermally grown SnO2 nanomaterials for improving photovoltaic performance of PSCs. The obtained results in this work provide the research community with an insight into the general trend of morphological changes in SnO2 nanostructures influenced by different solvothermal growth parameters. This information can guide the researchers to prepare more reproducible solvothermally grown SnO2 nanomaterials for future application in devices. Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)
Show Figures

Figure 1

22 pages, 11081 KiB  
Article
Double Perovskite LaFe1−xNixO3 Coated with Sea Urchin-like Gold Nanoparticles Using Electrophoresis as the Photoelectrochemical Electrode to Enhance H2 Production via Surface Plasmon Resonance Effect
by Hsiang-Wei Tsai and Yen-Hsun Su
Nanomaterials 2022, 12(4), 622; https://doi.org/10.3390/nano12040622 - 12 Feb 2022
Cited by 5 | Viewed by 2494
Abstract
The surface plasmon resonance (SPR) effect and the hetero-junction structure play crucial roles in enhancing the photocatalytic performances of catalysts for the water-splitting reaction. In this study, a series of double perovskites LaFe1−xNixO3 was synthesized. LaFe1−xN [...] Read more.
The surface plasmon resonance (SPR) effect and the hetero-junction structure play crucial roles in enhancing the photocatalytic performances of catalysts for the water-splitting reaction. In this study, a series of double perovskites LaFe1−xNixO3 was synthesized. LaFe1−xNixO3 particles were then decorated with sea urchin-like Au nanoparticles (NPs) with the average size of approximately 109.83 ± 8.48 nm via electrophoresis. The d-spacing became narrow and the absorption spectra occurred the redshift phenomenon more when doping increasing Ni mole concentrations for the raw LaFe1−xNixO3 samples. From XPS analysis, the Ni atoms were inserted into the lattice of the matrix, resulting in the defect of the oxygen vacancy, and NiO and Fe2O3 were formed. This hybrid structure was the ideal electrode for photoelectrochemical hydrogen production. The photonic extinction of the Au-coated LaFe1−xNixO3 was less than 2.1 eV (narrow band gap), and the particles absorbed more light in the visible region. According to the Mott–Schottky plots, all the LaFe1−xNixO3 samples were the n-type semiconductors. Moreover, all the band gaps of the Au-coated LaFe1−xNixO3 samples were higher than 1.23 eV (H+/H2). Then, the hot electrons from the Au NPs were injected via the SPR effect, the coupling effect between LaFe1−xNixO3 and Au NPs, and the more active sites from Au NPs into the conduction band of the semiconductor, improving the hydrogen efficiency. The H2 efficiency of the Au-coated LaFe1−xNixO3 measured in ethanol was approximately ten times larger than the that of Au-coated LaFe1−xNixO3 measured in 1-butanol at any testing temperature because ohmic and kinetic losses occurred in the latter solvent. Thus, the activation energies of ethanol at any testing temperature were smaller. The maximum real H2 production was up to 43,800 μmol g−1 h−1 in ethanol. The redox reactions among metal ions, OH*, and oxides were consecutively proceeded under visible light illumination. Full article
(This article belongs to the Special Issue Solution-Processed Metal Oxide Nanostructures for Carrier Transport)
Show Figures

Figure 1

Back to TopTop