Effect of Temperature on Electro-Optical Characteristics of Silicon Based p-n Photodiode (VTB8440BH)

Abstract

To get useful information about the carrier transport mechanism we first measure the current-voltage (I-V) characteristics of a silicon p-n photodiode (VTB8440BH) in the temperature range 350 − 110 K. All semilog I-V curves exhibit three successive linearly dependent regions along with their bias levels which are defined as I, II and III regions, respectively. Regions I and II with different slopes are used to determine the bias dependent ideality factors namely, n1 and n2. The variation of n1 and n2 with temperature shows that with lowering of temperature the tunneling probability gradually increases. Furthermore, these results are used to identify the paramount carrier at different bias levels. Secondly, to acquire knowledge of electron-hole generation rate we measure the variation of photocurrent in the same temperature range. Results show that photocurrent decreases slowly as temperature decreases from 350 to 239 K and it changes sharply below 239 K. The change of photocurrent with temperature is explained in terms of temperature dependence of carrier mobility, lifetime and optical generation rate. Finally, these results will be helpful for precision application of the optoelectronics device in both high and low temperature ambience.