Ultrathin Passivation of P-type silicon Surface by Atomic Layer Deposited Gallium Oxide Thin Films

Abstract

Surface passivation performances of Ga2O3 thin films deposited on p-type Czochralski Si wafers by atomic layer deposition (ALD) were investigated as a function of post-deposition annealing conditions. Minority carrier lifetimes were characterized by Semilab WT-2000PVN lifetime tester. The average effective minority carrier lifetime can reduce to 218.09 μs after annealed treatment at the temperatures of 650 °C for 3 min. It found that the surface recombination velocities of Ga2O3 thin film (3.4 nm and 7.6 nm) decrease to ∼30 cm/s and are saturated with the annealing temperature of 600 °C ∼700 °C. Such results indicate that Ga2O3 thin film show the functions of surface passivation for photovoltaic applications.