Boron-Doped Zinc Oxide Electron-Selective Contacts for Crystalline Silicon Solar Cells with Efficiency over 22.0.

Abstract

The exploration of wide-bandgap metal compound films with excellent passivation and contact properties on crystalline silicon (c-Si) surface, as alternatives to traditional-doped Si thin films, holds significant promise for the future enhancement of c-Si solar cell efficiency. Herein, conductive boron-doped zinc oxide (ZnO:B) films are deposited by atomic layer deposition (ALD) process and investigated as electron-selective contacts, in combination with a thin SiO _x passivating interlayer. This combination demonstrates a relative low contact resistivity of ≈2 mΩ cm² and improved passivation quality. Further application of this SiO _x /ZnO:B stack as a full-area electron-selective passivating contact in proof-of-concept n-type c-Si solar cells results in a satisfactory power conversion efficiency of over 22.0%. This electron-selective passivating contact structure, prepared via low-temperature, simplified, and the compositionally controlled ALD process, offers a promising pathway for the development of high-efficiency and low-cost c-Si solar cells.