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

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 KBiO3 to combine with wider-band-gap NaBiO3 for KBiO3/NaBiO3 heterostructures by adding KOH into NaBiO3. The band gaps of the heterostructures change with the ratios of KOH:NaBiO3 in raw materials and are abnormally narrower than that of KBiO3. The interfaces between KBiO3 and NaBiO3 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 KBiO3 to NaBiO3. [Display omitted] •KBiO3/NaBiO3 heterostructures are constructed with different ratios.•The band gaps of KBiO3/NaBiO3 heterostructures are tailored by their interactions.•The SPV range of NaBiO3 is expanded from 475 to 600 nm by the heterostructures.