Passivation of Zn3P2 substrates by aqueous chemical etching and air oxidation

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 Br-2 in methanol exhibited surface recombination velocity values of 2.8 x 10(4) cm s(-1), whereas substrates that were further treated by aqueous HF-H2O2 exhibited surface recombination velocity values of 1.0 x 10(4) cm s(-1). Zn3P2 substrates that were etched with Br-2 in methanol and exposed to air for 1 week exhibited surface recombination velocity values of 1.8 x 10(3) cm s(-1), as well as improved ideality in metal/insulator/semiconductor devices. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4765030]