Photoelectrochemical hydrogen generation with linear gradient Al composition dodecagon faceted AlGaN/n-GaN electrode

We demonstrated photoelectrochemical cells (PECs) with dodecagon faceted AlGaN/n-GaN heterostructure electrode for H(2) generation, where the AlGaN/n-GaN heterostructure has a linear gradient Al composition (LGAC). The separation efficiency of the photo-generated electron-hole pairs in the electrode performs a key function in the H(2) generation efficiency of PEC cells. The linear gradient Al composition, AlGaN, could create more internal field and light absorption because of the linear graded band gap. Therefore, the zero-bias photocurrent density of PEC cells with dodecagon facet LGAC AlGaN/n-GaN heterostructure electrode is around 5.9 times larger than that of dodecagon faceted n-GaN electrode.