[19p-Z15-1~11] 6.4 Thin films and New materials

[19p-Z15-10] Photocathode Properties of Photoelectrochemically Constructed CuO/Cu₂O Bi-layers

〇Ryoga Yokoyama¹, Pei Loon Khoo¹, Masanobu Izaki¹ (1.Toyohashi Univ.)

Keywords:Cupper-oxide, Photocathode, Electrodeposited bi-layers

Copper oxide as a photocathode has been attracting attention due to its low-cost and low-toxicity. However, the efficiency of single-layer copper oxide is limited due to its bandgap, and a strategy to utilize multiple bandgaps of CuO-Cu₂O bi-layers has been proposed as a realistic candidate for a high-performance photocathode. The CuO/Cu₂O bilayer was prepared by photoelectrochemical potential-switching in a newly designed Cu-complex aqueous solution containing copper (II) sulfate hydrate and tartaric acid, and its structural, optical, and photoelectrochemical characteristics were evaluated under AM1.5 illumination. The photocurrent density showed improvement by stacking CuO/Cu₂O and annealing.