A Cost-Effective Long-Wave Infrared Detector Material Based on Graphene@PtSe[sub.2]/HfSe[sub.2] Bidirectional Heterostructure: A First-Principles Study

The Graphene@PtSe[sub.2] heterostructure is an excellent long-wave infrared detection material. However, the expensive cost of PtSe[sub.2] prevents its widespread use in infrared detection. In this paper, Hf was used to partially replace Pt to form Graphene@(PtSe[sub.2] )[sub.n] (HfSe[sub.2] )[sub.4−n] (n = 1, 2, and 3) bidirectional heterostructures consisting of graphene and lateral PtSe[sub.2] /HfSe[sub.2] composites based on first-principles calculations. Then, the new bidirectional heterostructures were compared with heterostructures formed by graphene with pure MSe[sub.2] (M = Pt, Hf). It was found that the band gaps of the bidirectional heterostructures were between those of Graphene@PtSe[sub.2] and Graphene@HfSe[sub.2] . Among these heterostructures, the Graphene@(PtSe[sub.2] )[sub.3] (HfSe[sub.2] )[sub.1] bidirectional heterostructure has almost the same optical absorption properties in the infrared wavelength region of 1.33~40 µm as the Graphene@PtSe[sub.2] heterostructure, and it improves the absorption in the near-infrared wavelength region of 0.75~1.33 µm. Such a designment may bring the material costs down (since PtSe[sub.2] costs approximately five times more than HfSe[sub.2] ). This study on the designment of the bidirectional Graphene@(PtSe[sub.2] )[sub.3] (HfSe[sub.2] )[sub.1] heterostructure also illustrates a cost-effective design method for Pt-based IR detectors.