One-Step Hydrothermal Synthesis of Sn-Doped Sb <sub>2</sub> Se <sub>3</sub> for Solar Hydrogen Production
Zhenbin Wang, Sanghyun Bae, Miloš Baljozović, Pardis Adams, David Yong, Erin Service, Thomas Moehl, Wenzhe Niu, S. David Tilley
Abstract
High Resolution Image Download MS PowerPoint Slide Antimony selenide (Sb 2 Se 3 ) has recently been intensively investigated and has achieved significant advancement in photoelectrochemical (PEC) water splitting. In this work, a facile one-step hydrothermal method for the preparation of Sn-doped Sb 2 Se 3 photocathodes with improved PEC performance was investigated. We present an in-depth study of the performance enhancement in Sn-doped Sb 2 Se 3 photocathodes using capacitance–voltage (CV), drive-level capacitance profiling (DLCP), and electrochemical impedance spectroscopy (EIS) techniques. The incorporation of Sn 2+ into the Sb 2 Se 3 results in increased carrier density, reduced surface defects, and improved charge separation, thereby leading to improved PEC performance. With a thin Sb 2 Se 3 absorber layer (270 nm thickness), the Sn-doped Sb 2 Se 3 photocathode exhibits an improved photocurrent density of 17.1 mA cm –2 at 0 V versus RHE ( V RHE ) compared to that of the undoped Sb 2 Se 3 photocathode (14.4 mA cm –2 ). This work not only highlights the positive influence of Sn doping on Sb 2 Se 3 photocathodes but also showcases a one-step method to synthesize doped Sb 2 Se 3 with improved optoelectronic properties.