Photoluminescent and photovoltaic properties observed in a zinc borate Zn2(OH)BO3

Abstract

A chiral zinc borate Zn₂(OH)BO₃, which exhibits nonlinear optical, photoluminescent and photoelectronic properties, has been successfully prepared through a hydrothermal reaction. The structure of the compound has a ZnO matrix and the electronic structure of the compound can be regarded as that for ZnO modified by the presence of B atoms. The luminescence properties of Zn₂(OH)BO₃ were characterized by excitation and emission spectra. Photovoltage signals were observed for the as-synthesized compound and for samples calcined at various temperatures by surface photovoltage spectroscopy (SPS) and field-induced surface photovoltage spectroscopy (FISPS). The results show that Zn₂(OH)BO₃ has photoelectric transformation ability. Either thermal treatment or application of an external electric field enhances the photovoltage responses of the compound to a considerable extent.