High-temperature ultraviolet detection based on InGaN Schottky photodiodes

A thermally stable metal-insulator-semiconductor (MIS) Schottky-type photodiode with high performance based on the InGaN film is demonstrated at high temperatures up to 523 K. The reverse leakage current remains at a low level (10(-7)-10(-8) A), while the UV responsivity is as high as 5.6 A/W at 3 V under 523 K, without observing the persistent photoconductivity. The discrimination ratio between ultraviolet (378 nm) and visible light (600 nm) is maintained to be more than 10(5). The temperature-dependent current-voltage characteristics of the MIS diode were analyzed. The photocurrent gain at reverse biases was interpreted in term of thermionic-field emission (TFE) and field-emission tunneling mechanism from room-temperature to 463 K, while TFE becomes the dominant mechanism at high temperatures. (C) 2011 American Institute of Physics. [doi :10.1063/1.3615291]