Effect of CdS/Mg-Doped CdSe Cosensitized Photoanode on Quantum Dot Solar Cells

Yingxiang Guan,Xiaoping Zou,Sheng He

doi:10.1155/2015/673135

Abstract

Quantum dots have emerged as a material platform for low-cost high-performance sensitized solar cells. And doping is an effective method to improve the performance of quantum dot sensitized solar cells (QDSSCs). Since Kwak et al. from South Korea proved the incorporation of Mg in the CdSe quantum dots (QDs) in 2007, the Mg-doped CdSe QDs have been thoroughly studied. Here we report a new attempt on CdS/Mg-doped CdSe quantum dot cosensitized solar cells (QDCSSC). We analyzed the performance of CdS/Mg-doped CdSe quantum dot cosensitized solar cells via discussing the different doping concentration of Mg and the different SILAR cycles of CdS. And we studied the mechanism of CdS/Mg-doped CdSe QDs in detail for the reason why the energy conversion efficiency had been promoted. It is a significant instruction on the development of Mg-doped CdSe quantum dot sensitized solar cells (QDSSCs).

Highlights

Doping of semiconductor quantum dot has been largely developed
It provides a broad way to achieve lowcost high-performance optoelectronic devices. Lee and his colleagues reported on a PbS:Hg quantum dot sensitized solar cells (QDSSCs) with high power conversion of 5.6% for the extremely high Jsc (30 mA/cm2) last year [1]
As we were enlightened by the previous research on doping [7,8,9] of our research group and the research on Mgdoped CdSe and CdS/CdSe photoanode structure of others, we report a quantum dot cosensitized solar cell prepared by using successive ionic layer absorption and reaction (SILAR) method based on cosensitized CdS/Mg-doped CdSe quantum dots (QDs). (Mg-CdSe stands for Mg-doped CdSe.)

Summary

Introduction

It provides a broad way to achieve lowcost high-performance optoelectronic devices Lee and his colleagues reported on a PbS:Hg QDSSC with high power conversion of 5.6% for the extremely high Jsc (30 mA/cm2) last year [1]. In 2007, Kwak et al proved that Mg was doped into CdSe with X-ray energy dispersive spectroscopy (EDS) and inductively coupled plasma mass spectrometry (ICPMS) [2] They adjusted the band-gap of CdSe nanocrystalline by doping CdSe with Mg which was blue shifted and the intensity of PL spectra of doped CdSe nanocrystalline was similar with that of undoped CdSe nanocrystalline, or even higher. Because of the Fermi level alignment, a stepwise structure of band-edge levels was yielded in the cascade structure of TiO2/CdS/CdSe electrode It profited the electron injection and hole recovery. As we were enlightened by the previous research on doping [7,8,9] of our research group and the research on Mgdoped CdSe and CdS/CdSe photoanode structure of others, we report a quantum dot cosensitized solar cell prepared by using successive ionic layer absorption and reaction (SILAR) method based on cosensitized CdS/Mg-doped CdSe QDs. (Mg-CdSe stands for Mg-doped CdSe.)

Methods

Results and Discussions

Conclusions