Improved Optoelectronic Performance of MoS₂ Photodetector via Localized Surface Plasmon Resonance Coupling of Double-Layered Au Nanoparticles with Sandwich Structure

Abstract

Two-dimensional (2D) MoS 2 has received much research interest because of its outstanding optical and electronic characteristics and is regarded as one of the most prospective semiconductors for application in future optoelectronic devices. Nevertheless, the low visible light absorption capacity and the long photoresponse time restrict its practical application in the field of photodetectors. Therefore, optoelectronic performance of 2D MoS 2 needs to be further improved. In this study, a MoS 2 flake modified by double-layered Au nanoparticles (NPs) with sandwich structure (Au−MoS 2 −Au) photodetector is designed and fabricated for the sensitive detection of visible light. Benefiting from the enhanced local surface plasmon resonance (LSPR) coupling between the upper and lower layers of Au NPs deposited on both sides of few-layered MoS 2 , double-layered Au NPs with sandwich structure is able to enhance visible light absorption and local electric field of MoS 2 . Accordingly, the optoelectronic performance of the Au−MoS 2 −Au photodetector is superior to that of MoS 2 modified with single-layered Au NPs. The peak photoresponsivity and specific detectivity of the Au−MoS 2 −Au photodetector are as high as 1757 A/W and 3.44 × 10 10 Jones, respectively. The response speed is estimated to be less than 24 ms. The present research may contribute to the development of a promising approach toward the design and fabrication of high-performance devices via LSPR coupling of double-layered metal NPs with sandwich structure.

Self-Powered Photodetector Based on a Ag Nanoparticle-Decorated Gd2O3 Nanorod

“…The variation in the switching response at different light intensities (0.86 to 2.59 mW/cm 2 ) can be attributed to the increased amount of photogenerated carriers with the increment in the incident power intensity. The rise and fall time was calculated from the switching response with 2.59 mW/cm 2 light intensity by exponential fitting with the equations, where I rise and I fall are the photocurrents at time t , A is the scaling constant, and τ is the time constant. On fitting the graph as shown in Figure d, the rise and fall time values were obtained as 0.18 and 0.17 s, respectively.…”

Ultrafast and Ultrabroadband UV–vis-NIR Photosensitivity under Reverse and Self-Bias Conditions by n+-ZnO/n-Si Isotype Heterojunction with >1 kHz Bandwidth

“…The figures indicate that the heterojunction device is also highly efficient under low power light of all the wavelengths and as the light intensity is increased gradually, an increase in the photocurrent has been observed. From the power law fitting 52 (I ph ∝ P Light α ), the power law coefficients (α) have been calculated from the log−log plot of I ph and P Light for all the wavelengths and shown in the insets in the corresponding figures. As the value of α lies between 0.5 to 0.7, the photocurrent increases sublinearly with the illumination intensity for all wavelengths.…”

Research Progress of Resonance Optical Fiber Sensors Modified by Low‐Dimensional Materials

“…In the field of the sensing region, the coupling effect between the LSPR characteristic of noble metal nanoparticles and the plasma wave on the surface of SPR sensor, the tips of these special structures can have the effect of local strong binding enhancing the field strength, which is attributed to the LSPR effect, which is one of the reasons for the sensitization effect of nanoparticles. [164][165][166][167] In addition, the adsorption of nanoparticles on the fiber surface increases the roughness of the sensing surface, and increases the surface area of the sensing region, thus improving the sensitivity of the sensor. [141] In addition to its own sensitization effect, porous nanoparticles can also fill their holes with sensitive materials, and the porous structure is conducive to the entry of the object to be measured into the particle and the full interaction with sensitive materials, thus facilitating the improvement of sensitivity.…”