A solution-processed octahedral nano-blocks structure CaIn 2 S 4 film for UV/vis photodetection.

A novel CaIn 2 S 4 with three-dimensional octahedral nano-blocks (ONBs) are successfully synthesized on fluorine-doped tin oxide (FTO) substrate by a simple hydrothermal method. The CaIn 2 S 4 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 CaIn 2 S 4 ONBs, a photodetector (PD) is fabricated. Satisfyingly, it is found that the CaIn 2 S 4 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 CaIn 2 S 4 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 CaIn 2 S 4 ONBs and plausible UV/vis detection mechanism of the CaIn 2 S 4 ONBs PD are discussed.