Heavy-metal-free colloidal semiconductor ZnSe nanoplatelets for UV photodetectors

Atomically flat two-dimensional colloidal semiconductor nanoplatelets manifest exceptionally sharp emission line width, ultrafast photoluminescence lifetime, high absorption cross-section and giant oscillator strength transition, making them advantageous over their counterparts such as spherical quantum dots and nanorods in a variety of applications in light-emitting devices, lasing, and photodetectors. Herein we report a solution-based process in fabricating a new type of ultraviolet (UV) photodetectors using colloidal ZnSe nanoplatelets synthesized by a wet-chemical method. The obtained UV photodetectors based on ZnSe nanoplatelets show a spectrum responsivity of similar to 3.5 mA W-1 at 365 nm and 0.6 mA W-1 at 254 nm, respectively, providing the basis for the application of such materials in UV spectral range photodetection.