Electrochemical deposition of GaTe thin films for photoelectrochemical applications

Abstract

GaTe thin lms are electrochemically deposited on indium tin oxide for photoelectrochemical applications. The electrochemical deposition behavior of GaTe in acidic solution of HTeO 2 + with Ga 3+ is studied with cyclic voltammetry combining with operando transmittance spectroscopy. Underpotential deposition of Ga on Te starts at potential of -0.35 V. The present of Ga 3+ in the solution can strongly suppressed the formation of H 2 Te. XPS analysis reveals that Ga-rich GaTe is deposited over a wide potential range. The photoelectrochemical performance of the thin lms as photocathodes is strongly dependent on the deposition potential. The GaTe lms deposited at -1.0 V produced the highest photocurrent of -0.06 mA cm − 2 with good stability. Meanwhile the lm deposited at -0.35 V shows improved performance during photoelectrochemical measurement, which can be ascribed to the increased GaTe content during photoelectrochemical measurements, as con rmed by XPS analysis.