Ultra-high performance self-powered radiation detector based on Si heterojunction

Self-powered detectors are highly significative in the applications of radiation detection in some harsh or limited space environment compared with the conventional detectors. Hence, we present a self-powered radiation detector with heterojunction structure formed by an ultra-thin oxide layer combined with heavily doped polycrystalline silicon layer. One outstanding advantage of the heterojunction structure is selective collection of carriers for lowering the recombination of signal carriers. The electrical characteristics were investigated from current-voltage and capacitance-voltage measurements, and the capability of radiation detection were performed by X-ray and alpha-sources. In the self-powered mode, detector showed low dark current of 1.5 nA/cm(2), good linear response to X-ray dose rate, perfect charge collection efficiency of more than 87%, and superior energy resolution within 2.2% for Pu-239 alpha-source spectral measurement. Besides, performance of the detector at the reverse bias from 0 V to 50 V were tested to further verify the detector's reliability.