The stretched-exponential law is used to describe the optically induced excess conductivity in compensated amorphous silicon. The results support the model of the slow trapping of photogenerated holes in P-B complexes which are in poor communication with the rest of the material, leaving electrons behind to conduct. The capture kinetics of the P-B center is related to the equilibration rate with a characteristic power-law time dependence.

• Received 30 May 1989

DOI:https://doi.org/10.1103/PhysRevB.40.3437