Bilayer MoOX/CrOX Passivating Contact Targeting Highly Stable Silicon Heterojunction Solar Cells

Jingye Li; Tianyu Pan; Jilei Wang; Shuangying Cao; Yinyue Lin; Bram Hoex; Zhongquan Ma; Linfeng Lu; Liyou Yang; Baoquan Sun; Dongdong Li

doi:10.1021/acsami.0c09877

Bilayer MoO_X/CrO_X Passivating Contact Targeting Highly Stable Silicon Heterojunction Solar Cells

ACS Appl Mater Interfaces. 2020 Aug 12;12(32):36778-36786. doi: 10.1021/acsami.0c09877. Epub 2020 Jul 28.

Authors

Jingye Li^{1

2}, Tianyu Pan¹, Jilei Wang³, Shuangying Cao¹, Yinyue Lin¹, Bram Hoex⁴, Zhongquan Ma⁵, Linfeng Lu¹, Liyou Yang³, Baoquan Sun⁶, Dongdong Li^{1

7}

Affiliations

¹ CAS Key Lab of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Zhangjiang Hi-Tech Park, Pudong, Shanghai 201210, China.
² School of Materials Science and Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, China.
³ Jinneng Clean Energy Technology Ltd., 533 Guang'an Street, Jinzhong 030600, China.
⁴ School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, 2052 Sydney, Australia.
⁵ Department of Physics, College of Sciences, Shanghai University, Shanghai 200444, China.
⁶ Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, P.R. China.
⁷ School of Microelectronics, University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.

PMID: 32667771
DOI: 10.1021/acsami.0c09877

Abstract

Molybdenum oxide (MoO_X, X < 3) has been successfully demonstrated as an efficient passivating hole-selective contact in crystalline Si (c-Si) heterojunction solar cells because of its large bandgap (∼3.2 eV) and work function (∼6.9 eV). However, the severe performance degradation coming from the instability of the MoO_X and its interfaces has not been well addressed. In this work, we started with a c-Si(p)/MoO_X heterojunction solar cell that yielded a power conversion efficiency (PCE) of 15.86%, in which the MoO_X film was synthesized by industry-compatible atomic layer deposition (ALD). The initial PCE dropped to 10.20% after 2 days because of severe migration of O and Ag at the MoO_X/Ag interface. We solved this by the insertion of a CrO_X layer between the MoO_X layer and the Ag electrode. The solar cell was found to be stable for more than 8 months in air because of the suppression of interface degradation. Our work demonstrates an effective way of improving the stability of silicon solar cells with transition metal oxide carrier selective contacts.

Keywords: atomic layer deposition; interface modification; molybdenum oxide; passivating contact; silicon heterojunction solar cell.