Recent advances in vacuum- and laser-based fabrication processes for solar water-splitting cells

The demand for zero-emission energy sources has recently intensified, driven by growing concerns over global warming and climate change. Among various renewable energy technologies, solar water-splitting cells have emerged as a promising avenue for harnessing hydrogen energy by exciting photo-carriers. These cells are typically fabricated using vacuum-based techniques such as physical vapour deposition, atomic layer deposition, chemical vapour deposition, and sputtering. Although these methods deliver moderate performance, they are characterised by extensive production steps and significant costs. This review examines the current vacuum-based fabrication processes for solar water-splitting cells and explores advanced or alternative techniques, with a particular emphasis on optical methods, especially laser processing, for fabricating these cells.