Comparison of Cu, Al, and Zr metallic contacts for chalcopyrite CIGS thin-film

Glass/Mo/CIGS was produced by the physical vapor deposition method and its morphological and structural characterizations were performed. The forbidden band gap and electron affinity values of the CIGS material were calculated depending on the element ratio of the EDS result obtained for CIGS thin films. The current-voltage (I-V) measurements of Cu/CIGS/Mo, Al/CIGS/Mo, and Zr/CIGS/Mo structures were taken at room temperature. While the Cu/CIGS structure exhibited ohmic behavior, rectifying behavior was observed for Al and Zr contacts. The zero-bias barrier height values for Al/p-CIGS and Zr/p-CIGS devices were calculated as 0.78 and 0.72 eV, respectively. The barrier heights determined from the experimental I-V measurements were lower than the barrier heights calculated using the Schottky-Mott model. When the contact characteristics of Al/CIGS and Zr/CIGS Schottky diodes were compared, Al performed better than Zr.