GeSe Photovoltaic Thin-Film Electrode for NIR Laser-Driven Hydrogen Evolution

Broadening the absorption spectrum of semiconductor materials, in other words, increasing the efficiency of photoelectrochemical water splitting devices for the use of sunlight is essential for efficient and economical hydrogen production. Over 50% of sunlight is infrared, but the vast majority of materials are unable to use this part of the energy due to the band gap, whereas the material used in this work, GeSe, has received a lot of attention and is being investigated for the decomposition of water due to its narrow band gap (1.1–1.3 eV), which gives it a wide absorption range. It can be seen that there is still room for improvement in the absorption of near-infrared (NIR) light, so we have used upconversion nanoparticles (UCNPs) to convert some of the NIR light into visible light, resulting in a significant overall utilization of sunlight and, ultimately, a 40% increase in the photocurrent of the GeSe photocathode in the NIR, and for the first time, we were surprised to find that the GeSe micro-air brick-based photocathode covered with Pt/C60 pat.–TiO2 ball spherical composite GeSe micro-air brick-based photocathodes exhibit excellent long-term stability under laser light for up to 10 h, which is crucial in the field of laser detection.