A new prospect to measure the built-in potential for photodiodes

Abstract

We present a novel approach to determine the built-in potential for photodiodes, which depends on the excitation of the photodiode by a pulsed or modulated light under forward bias. The proposed method was tested for commercially available photodiodes and the measurement results were compared with the values, which were obtained by conventional current-voltage and capacitance-voltage measurements. It was found that the proposed method gave consistent results with current-voltage and capacitance-voltage measurements. For the confirmation of the accuracy of this method, temperature dependent measurements were also performed for Si photodiode in a temperature range of 298 - 333 K to compare the obtained built-in potential values with theory. This analysis showed that the results of the proposed method were more reliable than the conventional measurements.