Regensburg 2025 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 20: Poster I

HL 20.4: Poster

Dienstag, 18. März 2025, 10:00–12:30, P3

Comparative Investigations of GaN/p-GaInP and p-GaInP Photocathodes: Stability and Performance in Acidic Electrolytes — •Sahar Shekarabi¹, Mohammad Amin Zare Pour¹, David Osteimer¹, Haoqing Su², Wentao Zhang², Agnieszka Paszuk¹, Wolfram Jaegermann³, Shu Hu², and Thomas Hannappel¹ — ¹Technische Universität Ilmenau, Institut für Physik, Ilmenau, Germany — ²Yale University, Department of Chemical and Environmental EngineeringNew Haven, USA — ³Technische Universität Darmstadt, Department of Materials and Earth Sciences, Darmstadt, Germany

GaInP(100) is a widely used photoabsorber in tandem solar cells and photoelectrochemical (PEC) devices. To enhance stability against photo-induced corrosion, GaN passivation layers have been employed. This study evaluates the stability of p-GaInP/GaN and p-GaInP electrodes for solar-driven hydrogen evolution reactions (HER) in 1.0 M HClO4. Faradaic efficiency was monitored via gas chromatography during PEC, while X-ray photoelectron spectroscopy and atomic absorption spectroscopy were used to investigate surface and dissolution process conditions. The large valence band offset of around 2.0 eV at the GaN/p-GaInP interface acts as a hole barrier, reducing recombination, while conduction band alignment facilitates electron transport. The GaN passivation layer enhances stability and achieves a low onset potential of -0.5 V for HER. Surface and electronic structural changes were analyzed to understand corrosion mechanisms.

Keywords: Water splitting; Hydrogen evolution reaction; GaN; III-V semiconductors