Enhanced photodetection through a perovskite BaTiO3 dielectric in a Si–MoS2 heterojunction

Abstract

The present investigation deals with the effect of a BaTiO₃ (BTO) dielectric layer on the performance of MoS₂/p-Si heterojunction photodetectors. The MoS₂/p-Si junction demonstrates a responsivity of ∼80 A W⁻¹ and detectivity of ∼10¹² Jones. The inclusion of a dielectric BTO layer significantly enhances the performance of MoS₂/p-Si photodetectors, leading to a remarkable improvement with a very high responsivity of ∼603 A W⁻¹ and detectivity of ∼10¹³ Jones. The I–V characteristics of the MoS₂/p-Si and MoS₂/BTO/p-Si junctions under illumination can be understood by considering their respective energy band diagrams. This addition alters the energy band alignment, leading to higher conduction band offset and valence band offset values. The large photocurrent in forward bias in the MoS₂/BTO/p-Si junction may be attributed to the presence of photogenerated electrons in the depletion region of BTO. BTO exhibits characteristics such as a long carrier diffusion length and low recombination rates, contributing to a reduction in carrier recombination within the photodetector for which the photocurrent of the MoS₂/BTO/p-Si heterojunction can be improved significantly. The enhanced performance of the MoS₂/BTO/p-Si junction, characterized by higher responsivity and detectivity, underscores the potential of this heterojunction for advanced photodetection applications, suggesting promising avenues for further research and development in the field of photodetectors. A comparative study with the available literature reveals that the excellent responsivity of ∼603 A W⁻¹ and detectivity of ∼10¹³ Jones of the presently studied MoS₂/BTO/p-Si heterojunction appear highly promising for various futuristic device applications.