Design and Optimization of SiOx/AZO Transparent Passivating Contacts for High-Efficiency Crystalline Silicon Solar Cells

A highly transparent passivating contact (TPC) used for high-efficiency crystalline silicon (c-Si) solar cells should meet several key criteria: high optical transparency, excellent c-Si surface passivation, low contact resistivity, and a low-temperature fabrication process suitable for device integration. Here, a simple TPC is developed structure consisting of a silicon oxide (SiOx) tunneling passivating layer and an aluminum doped zinc oxide (AZO) electron-selective transporting layer (SiOx/AZO). This TPC demonstrated remarkable passivation quality with a low contact recombination current density of below 2.2 fA cm(-2), an implied open-circuit voltage of close to 740 mV and a contact resistivity below 20 m Omega<middle dot>cm(2) when contact with lightly doped n-type c-Si. This excellent passivation performance can be attributed to improved interfacial hydrogen chemical passivation and the field-effect passivation induced by the highly Al-doped ZnO film. Demonstrated n-type c-Si solar cells using full-area SiOx/AZO rear contacts achieved a significant efficiency of 23.17%. Further power loss analysis based on numerical simulations outlines the pathway to achieving efficiencies exceeding 26%.