Frequency dependence of junction capacitance of BPW34 and BPW41 p-i-n photodiodes

Abstract

This article investigates the frequency dependence of small-signal capacitance of silicon EPW34 and BPW41 (Vishay) p-i-n photodiodes. We show that the capacitance-frequency characteristics of these photodiodes are well-described by the Schibli and Milnes model. The activation energy and the concentration of the dominant trap levels detected in BPW34 and BPW41 are 280-330 meV and 1.1 x 10(12)-1.2 x 10(12) cm(-3), respectively. According to the high-frequency C-V measurements, the impurity concentrations are determined to be about 5.3 x 10(12) and 1.9 x 10(13) cm(-3) in BPW41 and BPW34, respectively using the method of Delta V/Delta(C-2) vs. C.