Photoelectrochemical measurement of effective diffusion length of carriers in lamellar semiconductors. Application to InSe

Owing to the anisotropy of the optical and electronic properties of layered materials, the photocurrent density (or the quantum efficiency) delivered by a lamellar semiconductor/electrolyte junction is dependent upon both the angle of incidence and the angle of polarization of the incoming light beam with respect to the crystallographic axis of the electrode. This dependence is analytically described and it is shown that this result can be used to measure the photogenerated minority carrier effective diffusion length in this family of materials. In a second part, this method of measurement is applied to the III-VI compound InSe. The conclusions agree very well with the values of diffusion lengths published previously. Revue Phys. Appl. 23 (1988) 1375-1382 AOÛT 1988,