MoS₂/Paper Decorated with Metal Nanoparticles (Au, Pt, and Pd) Based Plasmonic‐Enhanced Broadband (Visible‐NIR) Flexible Photodetectors

Abstract

development of flexible electronics, especially in the biomedical field, which has led to an exploration of flexible substrate photodetectors. [7,8] These devices are far more compact and cost-effective compared to the conventional bulk substrate devices and reduce the expenditure on material as well as fabrication. [9] Still, several issues need to be addressed. [10] Some of the issues are surface roughness, thermal stability, and cleanroom compatibility. Almost all of the flexible substrates utilized (polymers, paper, textile, etc.) have a rough surface which not only affects the charge carrier mobility but also increases the recombination rate. Further, the rise time is also affected which affects the gain of the photodetector. The second is thermal stability, that is, most of the flexible substrates cannot withstand high temperatures, and hence performing high-temperature processes is not possible which restricts limited fabrication methodologies. [11] Last, the flexible substrates are not cleanroom compatible and novel methodologies need to be developed for integrating novel functional nanomaterials onto the flexible substrates. Novel functional materials ranging from 0D to 2D, and hybrids (0D-1D, 0D-2D, and 1D-2D) based on these materials have been explored for this purpose. [12-15] Piezotronics is another means to improve the responsivity upon application of external strain which modulates the depletion region width and increases the electric field and thereby the responsivity. But the issue with piezotronics is that, the application of strain leads to permanent damage in the device, thereby decreasing the reliability of the photodetector. Localized surface plasmon resonance (LSPR) is another means of increasing the absorption, and hence the responsivity and speed, and is a widely researched domain for conventional rigid substrate devices with the decoration of noble nanoparticles (NPs). [16-19] However, reports on the use of metal NPs for high-performance flexible devices using LPSR are few. Moreover, the reports on the comparative performance of different NPs also remain limited. Hence, there is a need to explore Plasmonic enhancement in flexible substrate devices. Transition metal dichalcogenides (TMDs) are a popular class of 2D materials because of their outstanding optical and mechanical properties and tunable bandgap. [20] Of these, MoS 2 is of special interest due to its superior electrical properties, high Even though there are reports on flexible photodetectors, one of the main issues that still needs to be resolved is the lower values of responsivity arising due to the use of non-conventional substrates such as polymers, cellulose paper, etc. There are ways to improve the responsivity, such as piezotronics and surface plasmonic resonance, but studies on utilizing the same for flexible substrates remain limited. Further, the comparative performance of different nanoparticles (NPs) remains unexplored. This report demonstrates the fabrication of flexible visible/near-infrared (NIR) photodetectors by...

Plasmon Triggered, Enhanced Light–Matter Interactions in Au–MoS2 Coupled System with Superior Photosensitivity

“…On the other hand, Guo et al prepared Au NSs on MoS 2 surface using magnetron sputtering that showed a responsivity of only 64 mA/W over the 700–1600 nm wavelength region . Very recently, Selamneni et al used solution of various metal NPs (Au, Pt, and Pd) to coat the MoS 2 surface and demonstrated flexible photodetectors with a peak responsivity of 99.3 and 46.03 mA/W under visible and NIR regions . The low responsivities of the reported studies are ascribed to the inefficient transfer of electrons from metal to semiconductor.…”

Spontaneous formation of gold nanoparticles on MoS2 nanosheets and its impact on solution-processed optoelectronic devices

“…The rise time was found to be 17.8 ms and the decay time was found to be 16.8 ms. A comparison of the figures of merit for our photodetectors and literature reported photodetectors are provided in the supporting information ( Table S1 ). The devices demonstrated here perform superior to reported MoS 2 based photodetectors with Au nanoparticles in terms of responsivity and response time ( Guo et al., 2019 ; Lin et al., 2020 ; McManus et al., 2018 ; Rahmati et al., 2019 ; Selamneni et al., 2021 ). Comparisons with reports on solution-processed transition metal dichalcogenide-based photodetectors have also been made ( Abid et al., 2019 ; Alzakia et al., 2020a , 2020b ; Kim et al., 2021 ; Li et al., 2020a ; Liu et al., 2019 ; McManus et al., 2017 ; Pulikodan et al., 2020 ; Seo et al., 2019 ).…”

Hybrid 0D–2D WS2-QDs (n)/SnS (p) as Distributed Heterojunctions for Highly Responsive Flexible Broad-Band Photodetectors

“…The XRD pattern of synthesized SnS is well-matched with JCPDS No. 39-0354, indicating an orthorhombic structure. , Further, two more peaks located at 22 and 16° are attributed to the paper substrate . XPS results were used to validate the chemical composition of the SnS.…”