Effect of post-annealing on the significant photoresponsivity enhancement of BaSi2 epitaxial films on Si(111)

Abstract

Abstract We demonstrated the marked photoresponsivity enhancement of BaSi2 epitaxial films by 5 min post-annealing at 850 °C–1000 °C in contrast to those at 600 °C–800 °C. Post-annealing at 1000 °C increased the photoresponsivity up to 9.0 A W−1 at a wavelength of around 800 nm under a bias voltage of 0.5 V applied between the top and bottom electrodes. The hole concentration decreased monotonously with annealing temperature from 8.3 × 1016 to 5.4 × 1015 cm–3, and the mobility exceeded 1000 cm2 V–1 s–1. The a-axis orientation of the BaSi2 films was significantly deteriorated at temperatures higher than 800 °C.