High quantum efficiency AlGaN solar-blind p-i-n photodiodes

摘要

We report AlGaN-based back-illuminated solar-blind ultraviolet p-i-n photodetectors with a peak responsivity of 136 mA/W at 282 nm without bias. This corresponds to a high external quantum efficiency of 60%, which improves to a value as high as 72% under 5 V reverse bias. We attribute the high performance of these devices to the use of a very-high quality AlN and Al_(0.87)Ga_(0.13)N/AlN superlattice material and a highly conductive Si-In co-doped Al_(0.5)Ga_(0.5)N layer.