Tailoring band gaps of KBiO3-NaBiO3 heterostructures by the interface actions for enhancing visible light photoelectric response

Abstract

Heterostructures with wide and narrow band gap semiconductors may harvest short and long wavelength light for enhancing photoelectric response. Here we adopt narrower-band-gap KBiO 3 to combine with wider-band-gap NaBiO 3 for KBiO 3 /NaBiO 3 heterostructures by adding KOH into NaBiO 3 . The band gaps of the heterostructures change with the ratios of KOH:NaBiO 3 in raw materials and are abnormally narrower than that of KBiO 3 . The interfaces between KBiO 3 and NaBiO 3 change with their ratios and then their interactions vary. The width and intensity of surface photovoltage spectra of the heterostructures increase notably in the visible light region, which results from prolonged lifetime of photogenerated electrons transferring from KBiO 3 to NaBiO 3 . • KBiO 3 /NaBiO 3 heterostructures are constructed with different ratios. • The band gaps of KBiO 3 /NaBiO 3 heterostructures are tailored by their interactions. • The SPV range of NaBiO 3 is expanded from 475 to 600 nm by the heterostructures.