Spectroscopic evidence of photogenerated carrier separation by built-in electric field in Sb-doped n-BaSi_2/B-doped p-BaSi_2 homojunction diodes

摘要

The operation of a BaSi2 homojunction solar cell is first demonstrated. In n(+)-BaSi2 (20 nm)/p-BaSi2 (500 nm)/p(+)-BaSi2 (50 nm) homojunction diodes on p(+)-Si(111) (resistivity p 0.01 Omega cm), the internal quantum efficiency (IQE) under AM1.5 illumination becomes pronounced at wavelengths lambda 800 nm and exceeded 30% at lambda = 500 nm. In contrast, the IQE values are small at lambda 600 nm in n(+)-BaSi2 (300 nm)/p-Si (p 0.1 Omega cm) heterojunction diodes, but are high in the range between 600 and 1200 nm. The difference in spectral response demonstrates the photogenerated carrier separation by the built-in electric field in the homojunction diode. (C) 2018 The Japan Society of Applied Physics