Effects of Mg composition on open circuit voltage of Cu2OMg xZn1-xO heterojunction solar cells

Ziqing Duan, Aurelien Du Pasquier, Yicheng Lu, Yi Xu, Eric Garfunkel

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59 Citations (Scopus)

Abstract

MgxZn1-xO (0≤x≤0.13) films grown by metal-organic chemical vapor deposition (MOCVD) were chosen as the n-type semiconductor layer forming a heterojunction with electrodeposited p-type cuprous oxide (Cu2O) for photovoltaic applications in this study. We investigated the effects of Mg contents (x) on the performance of AgCu 2OMgxZn1-xOfluorine-doped tin oxide (FTO)-glass heterojunction solar cells, where Ag and FTO are used as top and bottom electrodes, respectively. An enhancement of the open-circuit voltage (V OC) with the increase of x, from 251 mV at x=0 to 570 mV at x=10%, was observed. In order to understand how VOC increases with Mg%, the band alignment between Cu2O and MgxZn1-xO was demonstrated using X-ray photoelectron spectroscopy (XPS) measurements. The result indicates that the conduction band of MgxZn1-xO moves closer to the vacuum level with increasing of x, leading to a decrease of the conduction band offset between MgxZn1-xO and Cu 2O and hence an enhancement of theoretical VOC. Another improvement with the increase of Mg% was realized on the shunt resistance (Rsh) of devices. With the improved VOC and R sh, a relatively high solar power conversion efficiency (ηAM1.5=0.71%) was obtained on the MgxZn 1-xO (x=10%) based solar cell.

Original languageEnglish
Pages (from-to)292-297
Number of pages6
JournalSolar Energy Materials and Solar Cells
Volume96
Issue number1
DOIs
Publication statusPublished - Jan 1 2012

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Keywords

  • Cuprous oxide (CuO)
  • Electrodeposition
  • MOCVD (metal-organic chemical vapor deposition)
  • Solar cells
  • Zinc oxide (ZnO)

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films

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