One-pot synthesized Bi ₂ Te ₃ /graphene for a self-powered photoelectrochemical-type photodetector

Abstract

Abstract Bismuth telluride (Bi 2 Te 3 ) is a typical topological insulator, which possesses a narrow band gap and exhibits fascinating performance in the photodetector field. In this work, we fabricated a Bi 2 Te 3 /graphene heterostructure via a facile one-pot hydrothermal method. The as-prepared composites were used as the electrode materials for the photoelectrochemical (PEC)-type photodetector. From the results of PEC tests, we obviously found that the Bi 2 Te 3 /graphene heterostructure offers a remarkable improvement in photoresponse compared to that of sole Bi 2 Te 3 , and effectively demonstrates effective photocarrier generation and transfer at the interface between the graphene and Bi 2 Te 3 , which can enhance the properties of the photoresponse. Moreover, owing to the self-powered ability of the PEC-type photodetector, it can work under the bias potential of 0 V and exhibits a prominent photoresponse which can reach 2.2 mA W −1 . Also, the photocurrent density of the prepared Bi 2 Te 3 /graphene heterostructure-based photodetector can almost linearly rise with the increased irradiation power density. Even if the light intensity was reduced to 40 mW cm −2 , the photocurrent density could also reach 67 μ A cm −2 , which ensures the photodetection ability of the as-prepared Bi 2 Te 3 /graphene under low light intensity. The excellent performance of a Bi 2 Te 3 /graphene heterostructure for a PEC-type photodetector holds great promise in the field of photoelectric detection.