Low-voltage Silicon p-i-n Photodiode with Increased Collection Coefficient of Minority Charge Carriers and Responsivity

The effect of crystal thickness on the photovoltaic parameters of silicon photodiodes, in particular, the collection coefficient of minority charge carriers and responsivity, was investigated. Taking into account that the investigated photoiodides had a significant area, a decrease in the crystal thickness provoked a decrease in their mechanical strength. It is proposed to increase the mechanical strength of crystals by thinning only the projections of the sensing elements on the reverse side. It is shown that reducing the thickness of the photodiode crystal from 500 µm to 300 µm allows obtaining samples with a 25% higher sensitivity at a reverse voltage of 2 V due to an increase in the intensity of radiation absorbed in the space charge region and a crystal thickness equal to the diffusion length of minority charge carriers after reflection from the gold layer. It was also found that the proposed photodiodes had a lower dark current and a slightly higher capacitance than the serial ones. When measuring the spectral characteristics of the sensitivity, it is seen that the proposed photodiode has a higher sensitivity in the entire wavelength range in which it is sensitive