The photoelectric performance of quantum dots (QDs)-based nanocomposites is closely related to the optical properties of QDs, which play a critical role in the optical absorption and separation/transfer of charge carriers. Herein, we report a nanocomposite composed of light absorber PbS
1−xSe
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The photoelectric performance of quantum dots (QDs)-based nanocomposites is closely related to the optical properties of QDs, which play a critical role in the optical absorption and separation/transfer of charge carriers. Herein, we report a nanocomposite composed of light absorber PbS
1−xSe
x quantum dots (QDs), electron-conducting multiwalled carbon nanotubes (MWCNTs) and hole-conducting poly-3-hexylthiophene (P3HT) with tunable photoelectric conversion performance. In addition to using the quantization effect, we proposed solid-solution PbS
1−xSe
x QDs (x = 0, 0.25, 0.5, 0.75, 1) for band gap engineering. In particular, we successfully synthesized relatively small (~5.3 nm) and uniform QDs via the hot-injection method by using PbCl
2, S/Se powder and environmentally friendly oleylamine (OLA) as the precursors and/or solvent. By increasing the content of Se, the band gap of PbS
1−xSe
x QDs decreased along with the decrease in the conduction band and valence band edges. The suitable energy level alignment enabled the efficient transfer of photoinduced charge carriers, and hence a much higher photoelectric conversion performance of the PbS
1−xSe
x-QD@MWCNT/P3HT nanocomposites than the individual QDs, P3HT, and binary PbS
1−xSe
x-QD@MWCNT, as well as the best performance, was achieved over PbS
0.75Se
0.25-QD@MWCNT/P3HT.
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