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°C, 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.