Kaustuv Das

Silver nanoparticle (NP)-decorated molybdenum disulfide (MoS₂) microflowers are presented as a novel platform for high-performance, self-powered broadband photodetectors. In this work, MoS₂ microflowers embedded with optimally sized Ag NPs are synthesized via a, eliminating post-deposition processes and enabling uniform NP distribution with strong plasmon–semiconductor interaction. The resulting device exhibits a broad photoresponse from 400 nm to 1100 nm, covering the visible to near-infrared spectrum. Under low illumination (2 µW cm⁻²), it achieves a responsivity of ∼1.9 × 10² A W⁻¹ and a specific detectivity of ∼4.61 × 10¹¹ Jones at bias voltage of 5.0 V, significantly outperforming most reported Ag–MoS₂ systems. This enhanced performance is attributed to efficient plasmon–exciton coupling and hot electron injection facilitated by the Ag NPs. Importantly, the device generates a measurable photocurrent at zero bias, confirming truly self-powered operation. As a proof of concept, the photodetector is integrated into a real-time optical communication setup, successfully receiving and decoding alphanumeric and binary signals. These results highlight the technological promise of in-situ plasmonic 2D semiconductor hybrids for next-generation, broadband, low-power optoelectronic applications.

This study focuses on developing high-performance near-infrared photodetectors using an MoS2/Si nanowire array (NWA) heterostructure decorated with plasmonic silver nanoparticles (AgNPs). Three-dimensional MoS2 stacked on vertical Si NWAs forming the heterostructure shows a broad spectral response from 400 to 1100 nm with a peak response at around 900 nm. The surface-plasmonic AgNPs significantly enhanced the detectivity of the photodetector. The AgNPs distributed on the MoS2 surface triggered plasmon–exciton coupling, resulting in higher light absorption and improved charge carrier separation. AgNPs/MoS2/Si NWAs had shown a high responsivity of 110 A/W and detectivity of 9 × 1010 Jones, which were threefold higher than that obtained heterostructure without plasmonic nanoparticles. The photodetector also shows a responsivity of 1.0 mA/W in the self-powered mode.

Few-layer transition metal dichalcogenides and perovskites are both promising materials in high-performance optoelectronic devices. Here, we developed a self-driven photodetector by creating a heterojunction between few-layer MoS₂ and lead-free perovskite Cs₂CuBr₄. The detector shows a unique property of very high sensitivity in a broad spectral range of 400 to 800 nm with response speed in a millisecond order. Current-voltage characteristics of the heterojunction device show rectifying behavior, in contrast to the ohmic behavior of the MoS₂-based device. The rectifying behavior is attributed to the type II band alignment of the MoS₂/Cs₂CuBr₄ heterojunction. The device shows a broadband (400 to 800 nm) photodetection with very high responsivity reaching up to 2.8 × 10⁴ A/W and detectivity of 1.6 × 10¹¹ Jones at a bias voltage of 3 V. The detector can also operate in self-bias mode with sufficient response. The photocurrent, photoresponsivity, detectivity, and external quantum efficiency of the device are found to be dependent on the illumination power density. The response time of the device is found to be ∼32 and ∼79 ms during the rise and fall of the photocurrent. The work proposes a MoS₂/Cs₂CuBr₄ heterostructure to be a promising candidate for cost-effective, high-performance photodetector.