Photoresponse-Bias Modulation of a High-Performance MoS₂ Photodetector with a Unique Vertically Stacked 2H-MoS₂/1T@2H-MoS₂ Structure

Abstract

Monolayer 2H-phase MoS2-based photodetectors exhibit high photon absorption but suffer from low photoresponse, which severely limits their applications in optoelectronic fields. The metallic 1T phase of MoS2, while transporting carriers faster, shows negligible response to visible light, which limits its usage in photodetectors. Herein, we propose an ultrafast-response MoS2-based photodetector having a channel that consists of a 2H-MoS2 sensitizing monolayer on top of 1T@2H-MoS2. The 1T@2H-MoS2 layer has a thickness of several nanometers and is a mixture of metallic 1T-MoS2 and semiconducting 2H-MoS2, imparting metal-like properties to the photodetector. Compared with the monolayer 2H-MoS2 photodetector, we observed a drastic increase in the photoresponse of the 2H-MoS2/1T@2H-MoS2 vertically stacked photodetector to a value of 1917 A W–1. Owing to the presence of metallic 1T-MoS2 within the metal-like 1T@2H-MoS2, the performance of the 2H-MoS2/1T@2H-MoS2 vertically stacked photodetector is voltage bias-modulated with an external quantum efficiency (EQE) of up to 448,384% and a specific detectivity of up to ∼1011 Jones. The higher carrier density and higher mobility of the 1T@2H-MoS2 layer explain the better bias-modulated performance. In addition, the interface between 2H-MoS2 and 1T@2H-MoS2 ensures fewer dangling bonds and reduced lattice mismatching. Thus, this study presents an exclusive vertically stacked MoS2-based photodetector that lays the foundation for the development of photodetectors exhibiting higher photoresponse.

A facile photochemical strategy for the synthesis of high-performance amorphous MoS2 nanoparticles

“…Molybdenum disulde (MoS 2 ) nanomaterial has a wide scope of application in various elds including photocatalysis, 1-3 electrochemical catalysis, [4][5][6][7] electronic devices, 8,9 optoelectronic devices, 10,11 sensors, 12,13 and environmental pollutant removal, [14][15][16][17] owing to its specic physico-chemical properties, such as relatively large surface area, strong adsorption capacity, adjustable band gap, abundant edge sites and good chemical stability. 18 Compared with crystals, short-range ordered and longrange disordered amorphous materials can offer large active surface areas with more defects and reaction sites.…”

Construction of multifunctional hydrogel based on the tannic acid-metal coating decorated MoS2 dual nanozyme for bacteria-infected wound healing

“…The characteristic BEs of S 2p 3/2 and S 2p 1/2 at 162.1 and 163.3 eV, respectively, corresponded to the Mo–S bonds in MoS 2 . The BEs of the Mo 3d signal of Mo 3d 5/2 and Mo 3d 3/2 at 229.3 and 232.3 eV, respectively, could be assigned to Mo(IV) in MoS 2 [ 35 ] ( Fig. 2 c).…”

Adaptive Hydrogels Based on Nanozyme with Dual‐Enhanced Triple Enzyme‐Like Activities for Wound Disinfection and Mimicking Antioxidant Defense System

“…The BEs for Mo 3d of Mo 3d 5/2 and Mo 3d 3/2 were at 229.3 and 232.3 eV, indexing to the Mo (IV) in MoS 2 (Figure 1n). [44] In addition, the peak at 235.8 eV was attributed to Mo oxides resulting from surface oxidation due to exposure to air. All these results demonstrated the successful synthesis of defective MoS 2 anchored on the CNT branches.…”