Injection photodiode based on an n-CdS/p-CdTe heterostructure

Abstract

The possibility of developing injection photodiodes with a tunable/reconfigurable? photosensitivity spectrum in the spectral range of 500–800 nm based on an n-CdS/p-CdTe heterostructure is shown. It is established that such a structure in the short-wavelength region λ = 500 nm has the highest spectral sensitivity Sλ ≈ 3 A/W in the forward direction at a bias voltage of V = +120 mV and Sλ ≈ 2 A/W in the reverse direction at a bias voltage of V = −120 mV. The integrated sensitivity of the device is Sint = 2 400 A/lm under illumination with white light E = 3 × 10−2 lx, at a bias voltage of V = +4.6 V, and temperature of T = 293 K. Upon illumination with the monochromatic light of an LG-75 laser with the wavelength λ = 625 nm, Sint = −1400 A/W (illumination power P = 18 × 10−6 W/cm2, bias voltage V = +4.6 V, and temperature T = 293 K). High values of Sλ and Sint provide the highly efficient transformation of light energy into electrical energy at low illumination levels (P < 18 × 10−6 W/cm2).