Ambipolar diffusion length measurements on hydrogenated amorphous silicon p-i-n structures

The determination of the ambipolar diffusion length within the i layer of a p-i-n structure made of hydrogenated amorphous silicon is reported for the first time. It is shown that this important parameter can be determined by measurements carried out on the entire structure. One finds for a typical cell structure that the measured diffusion length is 10–20% smaller than the true i-layer value.