Photoelectrical properties of Hg1-xCdxTe epitaxial films and photodiodes with composition grading

The photocurrent spectra are investigated in Hg 1 - x Cd x Te liquid phase epitaxy (LPE) films and photodiodes of n+-p type on their base with composition gradient. The LPE films were grown on CdTe and CdZnTe single crystalsubstrates. The transformation of the photocurrent spectra caused by the composition gradient is studied both experimentally and theoretically. The analytical expressions for the spectral dependencies of the photocurrent are derived from the solution of the one-dimensional continuity equation. The calculation of the photocurrent spectra are made in which the nonparabolicity of the energy bands in HgCdTe is taking into account.