Measurements on monocrystalline CuInSe/sub 2/ cells

A series of measurements has been made on a number of photovoltaic cells fabricated with the layer structure Au-CuInSe/sub 2/-CdS-ZnO-In, where the CuInSe/sub 2/ consisted of a wafer of p-type monocrystalline material cut from an ingot grown by a vertical Bridgman method. A plot of conversion efficiency (/spl eta/) and short circuit current density (j/sub SC/) against cell series resistance (R/sub AS/), obtained from dark current-voltage characteristics, indicated a general increase of /spl eta/ and j/sub SC/ with decrease of R/sub AS/. The measurements also showed a general increase of j/sub SC/ with increase of the apparent hole concentration, p/sub MS/, obtained from Mott-Schottky plot slopes. Minority diffusion length estimates, obtained by the photo-current-capacitance method, were found to decrease with increase of p/sub MS/. As a result, surprisingly, diffusion lengths were smaller in the better performance cells. The best monocrystalline CuInSe/sub 2/ cell had an original total area efficiency of 11.4% (or 12.5 %, active area), without an A.R. coating.