A solution-processed octahedral nano-blocks structure CaIn2S4 film for UV/vis photodetection

A novel CaIn2S4 with three-dimensional octahedral nano-blocks (ONBs) are successfully synthesized on fluorine-doped tin oxide (FTO) substrate by a simple hydrothermal method. The CaIn2S4 ONBs are uniform grown and scattered on the whole FTO substrate with high regular and symmetric morphology as well as average diagonal length of about 600 nm. Based on the as-synthesized CaIn2S4 ONBs, a photodetector (PD) is fabricated. Satisfyingly, it is found that the CaIn2S4 ONBs PD achieves a broad-band response ranging from ultraviolet (UV) to visible ( vis) light at zero bias voltage. It is also significant that the CaIn2S4 ONBs PD enables a fast response, in which the rise time and decay time are less than 0.15 and 0.2 s, respectively. Furthermore, the morphological evolution of the CaIn2S4 ONBs and plausible UV/vis detection mechanism of the CaIn2S4 ONBs PD are discussed.