Published online by Cambridge University Press: 11 January 2018
Thermal evaporation is a simple method to fabricate a BaSi2 film, a new solar cell material consisting of earth-abundant elements. In this study, we optimized the evaporation process and suppressed near-interface oxidation in evaporated BaSi2 films on Si(100) substrates, which has been detected in previous studies. Composition depth profiles determined by Auger electron spectroscopy show the decrease of oxygen concentration near the interface to the background level by optimizing the source pre-melting condition. By reducing oxygen concentration, the BaSi2 film becomes more preferentially oriented toward [100] as long as the deposition rate is not changed, as evidenced by X-ray diffraction. It is also shown that the rectification behavior of n-BaSi2/p+-Si diodes improves by suppressing the near-interface oxidation.