Enhancing the photoinduced hole transport in solid state quantum-dots solar cells: The case of CdSe

Solar cells based on colloidal quantum dots (CQDs) have achieved great progress in recent years. However, the stable and high performance all solid solar cells using CQDs as light absorber are numbered till now. In this work, CdSe CQDs solid state solar cells have been fabricated as a case for revealing the reasons of low photoelectric conversion efficiency. It finds that the inefficient photoinduced hole transport block the improvement of the photoelectric performance. For facilitating the hole transport, a thin PbS interlayer has been fitted between the CQDs and hole transport layer, and as a result the photocurrent receives about 7.8 times increase in the devices constructed with 5.1 nm CQDs. Finally, a 1.29% of PCE is obtained from the solar cells with FTO/TiO2/CdSe CQDs/PbS/ Sprio-MeOTAD/Ag structure.

Automated summary

Solid state solar cells using CQDs as light absorber have limited research, and this study fabricated CdSe CQDs solid state solar cells to investigate the reasons for low photoelectric conversion efficiency. It finds that the low efficiency of photoinduced hole transport blocks the improvement of the photoelectric performance. By adding a thin PbS interlayer between CQDs and hole transport layer, the photocurrent is increased by about 7.8 times in the devices constructed with 5.1 nm CQDs, resulting in a PCE of 1.29%.