One-step synthesized PbSe nanocrystal inks decorated 2D MoS2 heterostructure for high stability photodetectors with photoresponse extending to near-infrared region

Abstract

Two-dimensional layered transition metal dichalcogenides (TMDs) have been widely employed as functional materials in promising electronics and optoelectronic devices due to their unique physical and outstanding electronic properties. However, 2D MoS₂ as a representative TMDs semiconductor with a low light absorption ability and narrow spectra absorption range will extremely restrict their potential application for high-performance optoelectronics. To overcome this issue, 2D TDMs based heterostructure photodetectors have been successfully demonstrated in this work by integrating a one-step synthesis of air stability of semiconductor PbSe nanocrystal inks with 2D MoS₂. The PbSe/2D MoS₂ heterostructure photodetector exhibits a light-to-dark current ratio of ∼10², a high responsivity of 23.5 A W⁻¹, a detectivity of 3.17 × 10¹⁰ Jones, and stability in ambient conditions as well. Compared with the pristine 2D MoS₂ photodetector, the responsivity and detectivity of the PbSe/MoS₂ photodetector are improved by 512% and 483%, respectively. More importantly, the photoresponse of the PbSe/MoS₂ heterostructure photodetector can extend to the near-infrared (NIR) light region while still maintaining the responsivity and detectivity of 19.7 A W⁻¹ and 2.65 × 10¹⁰ Jones, respectively, under 808 nm light illumination. The reasons for the excellent performance of the PbSe/MoS₂ heterostructure photodetector have also been studied and discussed in detail in this work, which will shed light on constructing high-performance NCs/2D TMDs heterostructure optoelectronics.