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

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 S λ ≈ 3 A/W in the forward direction at a bias voltage of V = +120 mV and S λ ≈ 2 A/W in the reverse direction at a bias voltage of V = −120 mV. The integrated sensitivity of the device is S int = 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, S int = −1400 A/W (illumination power P = 18 × 10 −6 W/cm 2 , bias voltage V = +4.6 V, and temperature T = 293 K). High values of S λ and S int provide the highly efficient transformation of light energy into electrical energy at low illumination levels ( P < 18 × 10 −6 W/cm 2 ).