Passivation of Zn3P2 substrates by aqueous chemical etching and air oxidation

Abstract

Surface recombination velocities measured by time-resolved photoluminescence and compositions of Zn3P2 surfaces measured by x-ray photoelectron spectroscopy (XPS) have been correlated for a series of wet chemical etches of Zn3P2 substrates. Zn3P2 substrates that were etched with Br2 in methanol exhibited surface recombination velocity values of 2.8 × 104 cm s−1, whereas substrates that were further treated by aqueous HF–H2O2 exhibited surface recombination velocity values of 1.0 × 104 cm s−1. Zn3P2 substrates that were etched with Br2 in methanol and exposed to air for 1 week exhibited surface recombination velocity values of 1.8 × 103 cm s−1, as well as improved ideality in metal/insulator/semiconductor devices.