Author Affiliations
Abstract
1 School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China
2 School of Electronic and Information Engineering, Nanjing University of Information Science & Technology Binjiang College, Wuxi 214105, China
Understanding detailed avalanche mechanisms is critical for design optimization of avalanche photodiodes (APDs). In this work, avalanche characteristics and single photon counting performance of 4H-SiC n-i-p and p-i-n APDs are compared. By studying the evolution of breakdown voltage as a function of incident light wavelength, it is confirmed that at the deep ultraviolet (UV) wavelength region the avalanche events in 4H-SiC n-i-p APDs are mainly induced by hole-initiated ionization, while electron-initiated ionization is the main cause of avalanche breakdown in 4H-SiC p-i-n APDs. Meanwhile, at the same dark count rate, the single photon counting efficiency of n-i-p APDs is considerably higher than that of p-i-n APDs. The higher performance of n-i-p APDs can be explained by the larger impact ionization coefficient of holes in 4H-SiC. In addition, this is the first time, to the best of our knowledge, to report single photon detection performance of vertical 4H-SiC n-i-p-n APDs.
4H-SiC avalanche photodiode electron-initiated ionization hole-initiated ionization Chinese Optics Letters
2021, 19(9): 092501
南京大学 电子科学与工程学院 江苏省光电信息功能材料重点实验室, 南京 210023
常规的半导体紫外探测器波长响应范围宽, 而紫外光的应用具有较强的波长选择性, 如320nm波段的紫外光在医学方面有重要的应用, 因此, 具有高波长选择性的紫外探测器的研制有重要意义。文章采用GaN基p-i-n探测器结构, 通过在p区覆盖银纳米薄膜作为欧姆接触层和波长选择透射层, 成功制备了对320nm波段紫外光高选择性探测的紫外探测器, 器件性能如下: 70nm银层的紫外光透射率峰值超过30%, 器件在-5V偏压下的暗电流为10-12A量级, 响应峰值为0.06A/W, 响应峰发生在325nm处, 光谱响应峰半高宽约30nm。
p-i-n紫外探测器 银纳米薄膜 波长选择性 p-i-n ultraviolet detector GaN GaN Ag nanofilm wavelength selectivity
