Efficient PbS Quantum Dot Solar Cells with Both Mg-Doped ZnO Window Layer and ZnO Nanocrystal Interface Passivation Layer

Hao Ren; Ao Xu; Yiyang Pan; Donghuan Qin; Lintao Hou; Dan Wang

doi:10.3390/nano11010219

Efficient PbS Quantum Dot Solar Cells with Both Mg-Doped ZnO Window Layer and ZnO Nanocrystal Interface Passivation Layer

Nanomaterials (Basel). 2021 Jan 15;11(1):219. doi: 10.3390/nano11010219.

Authors

Hao Ren¹, Ao Xu¹, Yiyang Pan¹, Donghuan Qin¹, Lintao Hou², Dan Wang¹

Affiliations

¹ State Key Laboratory of Luminescent Materials & Devices, Institute of Polymer Optoelectronic Materials & Devices, South China University of Technology, Guangzhou 510640, China.
² Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Siyuan Laboratory, Department of Physics, Jinan University, Guangzhou 510632, China.

Abstract

In this paper, a Mg-doped ZnO (MZO) thin film is prepared by a simple solution process under ambient conditions and is used as the window layer for PbS solar cells due to a wide n-type bandgap. Moreover, a thin layer of ZnO nanocrystals (NCs) was deposited on the MZO to reduce carrier recombination at the interface for inverted PbS quantum dot solar cells with the configuration Indium Tin Oxides (ITO)/MZO/ZnO NC (w/o)/PbS/Au. The effect of film thickness and annealing temperature of MZO and ZnO NC on the performance of PbS quantum dot solar cells was investigated in detail. It was found that without the ZnO NC thin layer, the highest power conversion efficiency(PCE) of 5.52% was obtained in the case of a device with an MZO thickness of 50 nm. When a thin layer of ZnO NC was introduced between MZO and PbS quantum dot film, the PCE of the champion device was greatly improved to 7.06% due to the decreased interface recombination. The usage of the MZO buffer layer along with the ZnO NC interface passivation technique is expected to further improve the performance of quantum dot solar cells.

Keywords: Mg-doped ZnO; PbS; quantum dot; solar cells.