2D nonlayered tellurium nanosheets for self-powered photodetectors

Tellurium (Te) is a kind of multifunctional material attracting a great deal of interest. Herein, we described a substrate-free solution process to produce Te nanosheets (Te NSs) and build photodetectors (PDs) of photoelectrochemical (PEC) type based on them. The PDs are self-powered according to the photocurrent density about 0.28 µA cm −2 and the photo responsivity of 3.37 µA W −1 when the optical power is 80.2 mW cm −2 without any extrinsic voltage. They exhibit excellent photo-response switching behaviors with high responsivity (15.8 µA W −1 ) and rapid response time (~ 227 ms of the rise time and ~ 293 ms of the fall time) at 0.6 V potential, as well as great long-term stability and durability (storage in ethanol for 1 month). Simultaneously, we measured the photoelectric response after heating the solution to explore the effect of the solution temperature on the photoelectric properties of Te NSs. At a temperature of 70℃, the enhancement was leveraged to promote the photo-response to 14.3 µA W −1 . This work paved the way for developing higher performance PDs.