The optimum preparation of InSe nanosheets and research of photoelectric response characteristics

In this article, we report a facile solvothermal route, via using green and nontoxic absolute ethyl alcohol as the solvent and surfactant. Hydrazine hydrate is a reductant. A thin flake-like InSe nanocrystals successfully synthesized by a two-step solvothermal-annealing process. In addition, we have optimized the experimental conditions, included solvothermal time, annealing temperature and annealing time to explore the change in photoelectric response and analyzes the reason of enhancement of photocurrent densities from mechanism of photocurrent generation in detail. The InSe powders have shown a high absorption coefficient in the visible range (λ > 420 nm). By optimizing preparation conditions, the as-synthesized film of 180 °C, 12 h–250 °C, 2 h shows the highest photocurrent density of 15.9 µA cm−2 at 0.5 V (versus SCE) under visible light. Photocurrent densities of thin film samples increased by approximately 2.8 times that of unoptimized nanosheets. It was shown that InSe nanosheets have superior photoelectric response characteristics under visible light illumination.