Ultrahigh Responsivity of Diamond-based Solar-blind Photodetectors Using Hydrogen Plasma Treatment

Diamond-based solar blind deep ultraviolet (DUV) photodetectors (PDs) have attracted extensive attention due to their unique characteristics in extremely harsh environment. Until now, its low responsivity has not been sufficient to meet the needs of the application. Here, an ultrahigh performance diamond-based solar blind DUV PD was obtained by controlling the two-dimensional hole carrier concentration on the epilayer-free Ib-type diamond surface through adjusting the duration of hydrogen plasma treatment. The diamond-based PD with 30 min hydrogen plasma treatment exhibits an ultrahigh external quantum efficiency (EQE) of 9.4×106%, which are far superior to the previously reported diamond-based, AlGaN-based, and Ga2O3-based solar blind PDs. These results open up a facile route to prepare high-sensitivity photodetectors