Estimation of Interfacial Fixed Charge at AI_2O_3/SiO_2Using Slant-Etched Wafer for Solar Cell Application

摘要

AI_2O_3 with a negative fixed charge prepared by atomic layer deposition has been reported to improve surface passivation properties for Si-solar cell applications. The high negative fixed charge at the SiO_2/AI_2O_3 interface facilitates a low surface recombination velocity and a high effective lifetime, which result in greater performance. In this study, we adopted an effective method using a slant-etched sample with various thicknesses o f SiO_2 to estimate the charge densities of both the bulk and interface of AI_2O_3 deposited by atomic layer deposition. We found a direct correlation between lifetime and total charge density in AI2O3, which are strong functions of film thickness and annealing condition.