Photo and dark conductivity of doped amorphous silicon

Abstract

Abstract The photo and dark conductivity of boron‐ and phosphorus‐doped amorphous silicon is measured in the temperature range from 100 to 400 K, for various doping levels. Increasing doping generally decreases the activation energy of dark conductivity, down to 0.2 eV, and also decreases the σ 0 ‐value (extrapolation of dark conductivity for T → ∞). This lowering of σ 0 is explained by a temperature shift of the Fermi level plus a change in the conduction mechanism. The activation energy of photoconductivity is also lowered, at least by phosphorus doping, which is understood by an influence of doping on the tailing of the bands.