Results on monocrystalline CuInSe2 solar cells

An evaluation is presented of three photovoltaic cells having the layer structure Au–CuInSe2–CdS–ZnO–In, which were fabricated with monocrystalline p-type wafers cut from Bridgman-grown CuInSe2 ingots. On these cells, measurements were made, which included illuminated and dark current–voltage characteristics, capacitance–voltage characteristics, and estimation of minority carrier diffusion lengths by the photocurrent–capacitance method. The values of conversion efficiency, short-circuit current density, open circuit voltage, and fill factor, measured under sunlight, all increased from cell-to-cell with decrease of dark series area–resistance and also, in a general way, with increased Mott–Schottky slope hole concentration. The results also showed the existence of a possible correlation between estimated diffusion length and Mott–Schottky slope concentration. One cell yielded an initial solar conversion total area efficiency of 11.4% (active area efficiency, 12.5%) without an antireflection (AR) coating on a total cell area of 0.138 cm2.