Enhanced Responsivity of Photodetectors Realized via Impact Ionization

• Main Authors: De-Zhen Shen, Shuang-Peng Wang, Xiu-Hua Xie, Qian Qiao, Ji Yu, Chong-Xin Shan, Zhen-Zhong Zhang
• Format: Article
• Language: English
• Published: MDPI AG 2012-01-01
• Series: Sensors
• Subjects: photodetector; responsivity; impact ionization
• Online Access: http://www.mdpi.com/1424-8220/12/2/1280/

To increase the responsivity is one of the vital issues for a photodetector. By employing ZnO as a representative material of ultraviolet photodetectors and Si as a representative material of visible photodetectors, an impact ionization process, in which additional carriers can be generated in an insulating layer at a relatively large electric field, has been employed to increase the responsivity of a semiconductor photodetector. It is found that the responsivity of the photodetectors can be enhanced by tens of times via this impact ionization process. The results reported in this paper provide a general route to enhance the responsivity of a photodetector, thus may represent a step towards high-performance photodetectors.