Photocurrent collection in a Schottky barrier on an amorphous silicon-germanium alloy structure with 1.23 eV optical gap

Abstract
We report the result of voltage‐dependent photocurrent collection measurements in Pd Schottky barriers on an undoped a‐Si,Ge:H,F multilayer alloy structure with an effective optical gap of 1.23 eV. The hole mobility‐lifetime product (μτ)p, extracted from a fit of the voltage dependence of the photocurrent to the Hecht expression, is 7×109 cm2 V1. Our result is an important indication that it is possible to produce the low‐gap a‐Si,Ge:H,F alloys with the optoelectronic characteristics needed for efficient tandem solar cells.