Nanowire-Shaped MoS₂@MoO₃ Nanocomposites as a Hole Injection Layer for Quantum Dot Light-Emitting Diodes

Abstract

Molybdenum disulfides and molybdenum trioxides are structures that possess the potential to work as efficient charge transport layers in optoelectronic devices. In the present study, as opposed to the existing Mo-based nanostructures in flake, sheet, or spherical forms, an extremely simple and low-cost hydrothermal method is used to prepare nanowires (NWs) of MoS2@MoO3 (MSO) composites. The synthesis method includes several advantages including easy handling and processing of inexpensive precursors to reach stable MSO NWs without the need for an oxygen-free medium, which would facilitate the possibility of mass production of these nanostructures. The structural analysis confirmed the formation of MSO nanocomposites with different Mo valence states, as well as NWs of average length and diameter of 70 nm and 5 nm, respectively. In order to demonstrate their potential for optoelectronic applications, MSO NWs were blended into hole injection layers (HILs) in quantum dot-based light-emitting diodes (QLEDs). Electroluminescence measurements show a substantial enhancement in both luminance (from 44,330 to 68,630 cd.m–2) and external quantum efficiency (from 1.6 to 2.3%), based on the increase in the ratio of MSO NWs from 3 to 10%. Interestingly, the addition of 10% volume of MSO NWs resulted in a remarkably smoother HIL with improved current efficiency and stability in green-emitting QLEDs. The simplicity and cost-effective features of the synthesis method along with outstanding favorable morphology demonstrated their ability to enhance the QLED performance and mark them as promising agents for optoelectronics.

Exciton and Trion at the Perimeter and Grain Boundary of CVD-Grown Monolayer MoS2: Strain Effects Influencing Application in Nano-Optoelectronics

“…The use of different substrates (such as sapphire where the mismatch of the thermal expansion coefficient is minimal) − or precursors − may help in relieving a residual strain on the flakes. Also controlling the cooling of the flakes after the growth, down to room temperature, may affect the amount of strain related to the thermal expansion coefficient mismatch. , Yet, the growth-induced strain effects cannot influence the grown TMDC nanostructure with nanoscale dimension in two or three dimensions like nanowires − and quantum dots. ,,, Such nanostructures are naturally strain-relaxed.…”

Recent Progress in Self-Healable Hydrogel-Based Electroluminescent Devices: A Comprehensive Review

“…Another intriguing fabrication of electroluminescence using PMA-based hydrogel is reported in Ref. [ 83 ], where a composite of PMA and CuInS 2 quantum dots composites was developed [ 84 ]. The long-term stability of EL devices can be compensated by such composite means.…”

Enhanced Hole Injection in Blue Quantum‐Dot Light‐emitting Diodes Utilizing Dual Hole Injection Layer of PEDOT:PSS/Ti3C2Tx

“…Numerous research efforts are dedicated to interface engineering that aims at interface stability of ITO. [18][19][20][21][22] However, the poor electrical conductivity of metal oxides may increase the interfacial transfer resistance between the anode and PEDOT:PSS, which is not favorable for hole injection. A HIL with better matching energy level and good conductivity is expected to achieve both stability and efficiency improvement of blue QLEDs.…”