Control of the electrical properties of BaSi2 evaporated films for solar cell applications

摘要

BaSi2 is a new candidate for the absorber in earth-abundant thin-film solar cells. In this study, we found that carrier density in evaporated BaSi2 films can be controlled by deposition rate. First, it is shown that BaSi2 films are formed at a high average deposition rate up to 2.8×103 nm/min at 600 and 650 °C. Then, by Hall measurement, carrier (electron) density is shown to decrease with increasing deposition rate. The origin of the carrier is discussed considering the crystal quality evaluated by Raman spectroscopy. At last, using the lowest carrier-density film, rectification by n-BaSi2/p+-Si diode is demonstrated.