P-type InP thin films prepared by a non-vacuum process for photoelectrochemical water splitting

Abstract

Photoelectrochemical (PEC) water splitting has been considered as a promising way to produce hydrogen production. Herein, we present an inexpensive and simple method for preparing high active p-type InP thin films photocathode with Zn doped at 500 °C. The amount of dopant was optimized to obtain the high PEC activity films. Electrical measurements indicated that the optimized film had the hole mobility of 350 cm2V−1s−1 and carrier density of 7.5×1017 cm3. Optical measurements demonstrated the high absorption of 90% in 450–750 nm, and the bandgaps of the samples ranged from 2.08 eV to 2.3 eV. PEC test showed that the onset potential of the optimized InP thin film was about 0.35 V vs. RHE and the saturation photocurrent of 8 mA/cm2 occurred at -0.3 V vs. RHE. These results indicated that our p type InP thin films were a potential material in PEC devices.