D. Sengottuvelu, M. Majdoub, S. Nouranian, A.V. Sumant, N.R. Pradhan, A. Al-Ostaz
University of Mississippi,
United States
Keywords: quantum dots, 0D-2D heterostructure, optoelectronics, broadband, photodetector
Summary:
In recent years, there has been a growing interest in the development of photodetectors that can offer high responsiveness, while also being ultrathin and cost-effective. In particular, photodetectors based on 0D–2D hybrid-assembly heterostructures have emerged as promising candidates thanks to their unique physical, optical, and electrical properties. These photodetectors allow for separate and independent light absorption and carrier transportation, which enables greater control over their performance. We present a simple and efficient method for functionalizing MoS2 and WS2 transition-metal dichalcogenide quantum dots (0D) in an aqueous solution. Our synthesis involves optimizing critical parameters such as size, solubility, and surface functional groups to obtain high-quality materials with the desired optoelectronic properties. The presence of functional groups on the surface of the quantum dots increases their solubility and stability in an aqueous solution, preserving their fluorescence properties. Transmission electron microscopy shows that the prepared quantum dots are uniform and monodispersed, with an average particle size of 5-10 nm. We are currently using techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy to analyze the materials' properties and optimize the synthesis protocol before integrating them with monolayer graphene 2D material. In addition to this, we are also demonstrating the high photosensitivity broadband photodetector from UV-to-NIR using 2D/polymer hybrid structure, where NIR absorbing polymer transfer the charge carriers to the non-NIR absorbing encapsulated 2D semiconductor channel to yield high photoresponsivity.