Achievement

The growth and characterization of CuInSe2 and CuGaSe2 p-type material systems on n-type (100) silicon. In this study film deposition was obtained by RF magnetron sputtering using stoichiometric targets. Current-voltage characteristics of these diodes indicated that reasonable p-n junctions were obtained. From the diode reverse-bias capacitance measurements the doping concentration of the films was determined to be approximately 1 x 1020 cm-3 for CuInSe2 and 1 x 1021 cm-3 for CuGaSe2. The forward current of the devices increased by at least 2 orders of magnitude for CuGaSe2 and by about three orders of magnitude for CuInSe2 at a bias of 2 V when illuminated with a 75 W halogen lamp. Built-in-potentials (Vbi) between 0.5 - 0.7 V, were obtained from 1/C2 - V plots for diodes. A strong response to illumination from this type of diode shows that chalcopyrite material systems might possibly be combined to create tandem heterojunction solar cells.