Geminate and non−geminate recombination in a–Si:H

A number of recent measurements including xerographic discharge and a delay‐collection field technique have indicated that the photogeneration process in a‐Si:H is controlled by a geminate recombination process. This results in the primary quantum efficency being field dependent which could limit performance of solar cells using a‐Si:H. An extension of the delayed‐collection experiment has also allowed a direct study of the non‐geminate recombination process (i.e., the recombination of free electron‐hole pairs that avoid geminate recombination). The analysis of the experimental data shows that the non‐geminate recombination is diffusion‐controlled and that both bulk and surface losses are extremely slow. The efective recombination lifetimes, under the conditions of these experiments, can be as long as 10 milliseconds.