Direct Tellurization of Pt to Synthesize 2D PtTe2 for High-Performance Broadband Photodetectors and NIR Image Sensors

Platinum telluride (PtTe 2 ) has garnered significant research enthusiasm owing to its unique characteristics. However, large-scale synthesis of PtTe 2 toward potential photoelectric and photovoltaic application has not been explored yet. Herein, we report direct tellurization of Pt nanofilms to synthesize large-area PtTe 2 films and the influence of growth conditions on the morphology of PtTe 2 . Electrical analysis reveals that the as-grown PtTe 2 films exhibit typical semimetallic behavior, which is in agreement with the results of first-principles density functional theory (DFT) simulation. Moreover, the combination of multilayered PtTe 2 and Si results in the formation of a PtTe 2 /Si heterojunction, exhibiting an obvious rectifying effect. Moreover, the PtTe 2 -based photodetector displays a broadband photoresponse to incident radiation in the range of 200–1650 nm, with the maximum photoresponse at a wavelength of ∼980 nm. The R and D * of the PtTe 2 -based photodetector are found to be 0.406 A W –1 and 3.62 × 10 12 Jones, respectively. In addition, the external quantum efficiency is as high as 32.1%. On the other hand, the response time of τ rise and τ fall is estimated to be 7.51 and 36.7 μs, respectively. Finally, an image sensor composed of a 8 × 8 PtTe 2 -based photodetector array was fabricated, which can record five near-infrared (NIR) images under 980 nm with a satisfying resolution. The result demonstrates that the as-prepared PtTe 2 material will be useful for application in NIR optoelectronics.