Flexible Photodetectors with High Responsivity and Broad Spectral Response Employing Ternary Sn_xCd_1–xS Micronanostructures

Ultrasensitive, fast response, and broad spectral response flexible photodetectors (FPDs) would be desirable for advanced technology. Here, high purity tin cadmium sulfide (SnxCd1–xS) micronanostructures (nanobelts, tapered nanobelts with/without hexagonal tips, nanorods, nanocombs, and nanoflowers) were grown via a facile one-step chemical vapor deposition (CVD) route and utilized for fabrication of metal–semiconductor–metal (MSM) rigid/flexible nanodevices. Compared to pristine CdS nanobelts, the Raman spectrum of SnxCd1–xS nanobelts exhibits a 3 cm–1 red shift at room temperature. The temperature-dependent intensity ratio (I2LO/I1LO) varies from 1.21 to 1.89, reflecting improved electron–lattice interaction in the SnxCd1–xS nanobelts. In addition, a ternary nanobelt based rigid device sensitively responds to UV-Vis light with high responsivity (4.82 × 101 A/W), high external quantum efficiency (1.46 × 104%), and fast response speed (20 ms). Compared to pristine CdS nanobelt devices, it responds to a broader spectral range while maintaining outstanding photoconductive characteristics. Additionally, SnxCd1–xS nanobelt FPDs exhibited good mechanical and electrical stabilities with a performance comparable to those of rigid devices. The result indicates that the ternary SnxCd1–xS micronanostructures may be an excellent candidate to enhance the optoelectronic performances of micro/nanodevices.