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

Abstract

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 mΩ·cm2 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%.