Optical MTF and quantum efficiency analysis in a finite slab

The formula for quantum efficiency in a semiconducting material was first derived by Seib in 1974 for a semi-infinite slab of semiconducting material. Seib's first-order analysis considered the effect of absorption coefficient, minority carrier diffusion length and depletion width. However, for modem devices on epitaxial material, smart sensors, quantum well devices, etc., the semi-infinite slab approximation breaks down, Here, we present the derivation for a finite slab that considers the thickness of the layer as a fourth parameter. We present a case study analyzing quantum efficiency, and hence MTF, in epitaxial silicon versus bulk gallium arsenide. (C) 2002 Published by Elsevier Science Ltd.