Two-step hydrothermal synthesis of sodium tantalate nanoparticles with deep ultraviolet sensitivity

Abstract

A convenient two-step hydrothermal method was developed to synthesize water dispersible NaTaO₃ nanoparticles. The growth of the NaTaO₃ nanoparticles was retarded with the aid of a water soluble complex agent in the first step, such as citric acid, bicine, triacetin, and EDTA 2Na, which formed complexes with Ta⁵⁺. The sizes of the NaTaO₃ nanoparticles, ranging from 5 nm to 30 nm, could be tuned by adjusting the reaction time as well as the complexing agent. An ultraviolet photodetector was fabricated with the solution processed NaTaO₃ film as the active layer, which presented a sensitive response to 280 nm deep UV illumination with a light to dark current ratio of about 160 and a response time of about 50 ms.