Tandem Si Micropillar Array Photocathodes with Conformal Copper Oxide and a Protection Layer by Pulsed Laser Deposition

• DOI: 10.1021/acsami.9b14408
• Publication Date: 2019-10-16T21:54:34Z
• Authors: Pramod Patil Kunturu; Christos Zachariadis; Lukasz Witczak; Minh D. Nguyen; Guus Rijnders; Jurriaan Huskens
• Keywords: Photocurrent; Passivation; Photocathode; Pulsed Laser Deposition

This work demonstrates the influence of high-quality protection layers on Si-Cu2O micropillar arrays created by pulsed laser deposition (PLD), with goal to overcome photodegradation and achieve long-term operation during photoelectrochemical (PEC) water splitting. Sequentially, we assessed planar device designs various design parameters their PEC hydrogen evolution reaction. On substrates, a Cu2O film thickness 600 nm Cu2O/CuO heterojunction layer 5:1 ratio between CuO were found be optimal. The Si/Cu2O/CuO heterostructure showed higher PV performance (Jsc = 20 mA/cm2) as compared Si/Cu2O device, but devices did not show this improvement. Multifunctional overlayers ZnO (25 nm) TiO2 (100 employed PLD provide hole-selective passivation that acts against photocorrosion. A Si/ITO-Au/Cu2O/ZnO/TiO2/Pt stack was device. Under optimized conditions, photocathode Pt HER catalyst displayed photocurrent 7.5 mA cm-2 at 0 V vs RHE an onset potential 0.85 RHE, stable for 75 h.