Ongoing Projects
Objective
Self-powered near-infrared (NIR: 0.7–2.5 μm) deteSelf-powered near-infrared (NIR: 0.7–2.5 μm) detection technologies attract immense interest both from scientists and industry experts due to their vital applications in environmental monitoring, night vision, and imaging in remote locations. However, available conventional NIR photodetectors (PDs) are based on costly fabricated inorganic semiconductor materials or toxic heavy metal-containing quantum dots (QDs), which restrict their use in electronics and biomedical applications. Silver chalcogenide-based (Ag2E, E= S, Se, Te) QDs have recently joined as new promising toxic heavy metal-free materials for NIR detection, making them appealing from health and environmental safety perspectives. Nevertheless, the development of Ag2E-based NIR PDs is in its initial stage and far behind the commercially available devices due to the lack of protocols for device-relevant thin film fabrication with favourable device architecture. In this project, we propose a novel approach to solve this issue, which consists of two strategies: (i) chemical synthesis of small Ag2E and MAgE alloyed QDs followed by thin film preparation with favourable legend and thickness, (ii) PD architecture with proper electrode and electrode distance. To achieve this, the first strategy will develop synthesis protocols to control the size of Ag2E QDs and optimize their absorption and electronic properties by ligand exchange for NIR PDs application with different metal electrodes and electrode distances. In the next stage, the potential metal alloy will be introduced into Ag2E QDs by cation exchange, followed by studying the optical and electrical properties to optimize the synthesis and thin film quality for self-powered NIR PDs. In the last stage, the work will concentrate on the optimization of photodiodes using the best-suited Ag2E and MAgE QDs and demonstrate the application potential and related extensive characterization of these devices for upscaling.
duration
01.11.2024-31.10.2026 (IFW, first part of project running TU Dresden)
external source:
Type of action:
HORIZON TMA MSCA Postdoctoral Fellowships - European Fellowships
project scientist:
PhD: Andrey Iodchik
RTG: RTG 2767/project A8
fellowship holder: Amir Scheikhshoaei
source: Land Sachsen und EU
duration: 01.10.2023 bis 30.09.2026
amount: 61.200,00
Sächsische Aufbaubank (SAB) application number: 100670474
Vorhabensbeschreibung
In this project we will develop novel hybrid plasmonic‒excitonic nanostructures active in the near-infrared (NIR) region. As a material platform for the fabrication of these composite structures we choose copper chalcogenide (Cu2‒xA, where x = 0–1 and A = S, Se or Te) two dimensional (2D) nanocrystals. Our selection relies on polymorphism of Cu2‒xA which exhibits a range of different stoichiometries adapting various crystal phases and a feasibility of chemical transformations of these nanocrystals via cation exchange.The project will combine the following two main parts: 1) development of a direct colloidal synthesis of semiconductor Cu2‒xA 2D nanomaterials with well controlled dimensions and crystal structure and their chemical transformations via cation exchange reactions into semiconductor 2D metal chalcogenides, such as CdA, PbA, HgA, and Ag2A, including their hetero-structures; 2) fabrication of composite fluorescent‒plasmonic materials in the form of planar layered assemblies and investigation of interactions between the layers using advanced optical spectroscopy techniques. Degrees of compositional and structural manipulation of the 2D materials targeted in this project will go far beyond the existing state-of-the-art methods for their direct wet chemical synthesis as well as chemical vapor deposition or exfoliation. Control of their structure and composition is a key to the precise engineering of their optoelectronic properties. From practical point of view, the combination of semiconductor nanocrystals with high absorption coefficients and high photoluminescence quantum yields and nanoparticles with a strong plasmon resonance is promising for the improvement of the efficiency of optoelectronic devices. Such a concept is of great importance for the NIR region, where a high efficiency is difficult to achieve. The lack of synthetic protocols for the synthesis of NIR-active copper, lead, mercury, and silver chalcogenide 2D nanomaterials on one hand, and practically not investigated yet interactions between plasmonic and excitonic structures in the NIR region on the other, motivate us to pursue these goals. The work plan of the project is assigned to a doctoral researcher supported by two student assistants.This work is expected to have impact not only on the fundamentals of chemistry of colloidal 2D semiconductor nanomaterials and their synthetic methodology, but also to provide a range of various materials with a well-defined application potential. The resulting materials and structures with tunable photophysical properties will be very promising candidates for applications in solar cells, luminescent solar concentrators, LEDs, and photodetectors.
project leader: PD Dr. Vladimir Lesnyak
duration: 2023-2026
external source: DFG
project scientist: M.Sc. Varvara Alabusheva
project leader: Dr. Juliane Simmchen
scource: DFG GEPRIS - DFG financed projects
project duration: 2022- 2026
partner: Antonio Stocco, Strassburg