Effect of the tunnelling oxide growth by H2O2 oxidation on the performance of a-Si:H MIS photodiodes

In this work metal–insulator–semiconductor (MIS) photodiodes with a structure: Cr/a-Si:H(n+)/a-Si:H(i)/oxide/Au were studied, where the main objective was to determine the influence of the oxide layer on the performance of the devices. The results achieved show that their performance is a function of both oxide thickness and oxide density. The a-Si:H oxidation method used was the immersion in H2O2 solution. By knowledge of the oxide growth process it was possible to fabricate photodiodes exhibiting an open circuit voltage of 0.65 V and short circuit current density under AM1.5 illumination of 11 mA/cm2, with a response times less than 1 μs for load resistance <400 Ω, and a signal to noise ratio of 1×107.