Growth and structural characterization of Sb <sub>2</sub> Se <sub>3</sub> solar cells with vertical Sb <sub>4</sub> Se <sub>6</sub> ribbon alignment by RF magnetron sputtering
Giulia Spaggiari, Francesco Pattini, Danilo Bersani, Davide Calestani, Andrea De Iacovo, E. Gilioli, Francesco Mezzadri, Andrea Sala, Giovanna Trevisi, Stefano Rampino
Abstract
Abstract Sb 2 Se 3 , (ASe) thin-films were deposited as the absorber layers in photovoltaic solar cells using the radio frequency magnetron sputtering deposition technique. Starting from a binary target, high quality crystallization and good vertical alignment of Sb 4 Se 6 ribbons were attained at growth temperatures below 300 °C, and use of an additional selenization process was unnecessary for compensating Se loss. By the structural characterization of films grown on different substrates, a strong dependence of the ribbon orientation on the substrate type was verified. This study clearly confirms that the ribbon alignment is the key factor for enhancing the performance of Sb 2 Se 3 solar cells, in particular the short circuit current density ( J sc ). A photovoltaic efficiency of 0.24% and a J sc of 5 mA cm −2 were obtained by depositing ASe on Mo, in a CuInGaSe 2 -like solar cell structure (Al:ZnO/ZnO/CdS/ASe/Mo/Glass), while the J sc was boosted up to 27 mA cm −2 when the ASe solar cells were fabricated in superstrate configuration with an Au/ASe/CdS/FTO architecture, leading to an efficiency of 2.36%.