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A dual P‐layer 4H‐SiC p‐i‐n ultraviolet photodetector is proposed and studied. The modeling results of the photoelectric characteristics demonstrate the dual P‐layer structure could effectively reduce the recombination of the photogenerated carriers and separate more electron‐hole pairs near the surface of the device. And, the photodetector exhibits a significantly high response and detectivity, especially in the wavelength range of extreme ultraviolet to ultraviolet‐C. A high spectral response peak of 0.2 A/W corresponding to a quantum efficiency of 95.3% is achieved. Furthermore, an avalanche breakdown voltage as low as 182 V is observed. The dual P‐layer structure significantly presents an innovative approach for the advancement of future ultraviolet photodetectors applied in the detection at illumination wavelengths ranging from extreme ultraviolet to ultraviolet‐A. [ABSTRACT FROM AUTHOR]

4H‐SiC ultraviolet p‐i‐n photodiodes with four different epitaxial structures were fabricated. The experimental results prove that both a thin P+‐type Ohmic contact layer and a thick intrinsic layer were indispensible for a high‐performance ultraviolet p‐i‐n photodiode. A 4H‐SiC p‐i‐n photodiode with responsivity as high as 0.139 A/W at 278 nm incident wavelength was achieved. Meanwhile, within a certain wavelength range, the peak response wavelength of an ultraviolet p‐i‐n photodiode would be modulated by properly varying the thicknesses of P+‐type layer and the intrinsic layer. Moreover, the theoretical calculation was carried out to further authorise the experimental results. [ABSTRACT FROM AUTHOR]

Silicon carbide‐based quasi‐separated‐absorption‐multiplication ultraviolet avalanche photodiode (APD) with a small‐area multiplication region and a large‐area absorption region, which comprises of a p+nn− junction encircled by a p+n− junction, is proposed, and its optoelectronic performance is modelled. The modelling results show a 4H‐SiC APD with high performance can be achieved. Moreover, when operated at a low reverse bias (e.g. 5.0 V), the photodiode has almost the same optoelectronic characteristics as the 4H‐SiC p‐i‐n photodiode. It is noted that the device has benefited advantages of both conventional separate absorption and multiplication APD and p‐i‐n photodiode in the wavelength range of ultraviolet detection, which enable the dual operation models of the device. [ABSTRACT FROM AUTHOR]