Photoconductivity spectral characteristics of semiconductors with exponential fundamental absorption edge

An analysis has been performed of photoconductivity spectral characteristic s of semiconductors with an exponential fundamental absorption edge as func tions of the surface recombination rate and sample thickness. It is shown, in particular, that in crystals of CdxHg1-xTe (x approximate to 0.2) the sp ectral position of the photoconductivity maximum over a wide range of value s of these parameters can be used, with an error not exceeding 1%, to deter mine the effective band gap and, consequently, the composition of the mater ial. (C) 1999 American Institute of Physics. [S1063-7826(99)00411-1].