Self-powered α-GaOOH nanorod array/FTO photoelectrochemical photodetectors for solar-blind UV photodetection

We have grown α-GaOOH nanorod array/FTO structures with different precursor concentrations by hydrothermal processes without any seed layers. The optical bandgap is ∼5.1 eV, indicating their ability of solar-blind UV photodetection. Photoelectrochemical (PEC) properties of α-GaOOH nanorod array/FTO photodetectors as photoanodes shows self-powered solar-blind UV photodetection. Due to the similar width of depletion regions of α-GaOOH nanorod array/FTO PEC photodetectors with changing the precursor concentrations, the peak responsivity is nearly the same. And they also show the similar response time (decay processes) ranging from 0.061s to 0.072s. Compared with the reported bare α-GaOOH nanorod arrays or heterojunctions, the maximum responsivity of 0.29 mA/W at 245 nm is comparable. However, fast collection speed without block of these seed layers between nanorod arrays and FTO results in faster response speed of 0.012 s in this work. Therefore, this article provides basic research in realizing high-performance self-powered α-GaOOH PEC photodetectors without seed layers.