报告题目：NIR-emitting nanostructures, perovskite nanocrystals, and carbon dots as perspective materials for optoelectronics and medicine
报告人：Aleksandr P. Litvin 1,2
1 – College of Materials Science and Engineering, Jilin University, Changchun, China
2 – PhysNano Department, ITMO University, Saint-Petersburg, Russia
报告时间：2023年05月19日，下午3:00~4:30
报告地点：激光楼116（多功能厅）
报告人简介：
Aleksandr P. Litvin received his PhD in Optics in 2015 from ITMO University (St. Petersburg, Russia). From 2020 to 2022 he headed the Laboratory “Optics of Quantum Nanostructures” at the same university. He is currently a postdoctoral researcher at College of Materials Science and Engineering of the Jilin University. His main scientific interests are optical spectroscopy of near-infrared emitting nanostructures, including quantum dots, nanoplatelets, and perovskites, energy and charge transfer phenomena between nanoparticles, and their utilization in optoelectronic devices.
报告主要内容：
In recent decades, nanoscale materials have attracted a lot of research attention due to their unique properties. At the same time, recent years have been marked by the emergence of new materials that can become the basis for creating devices in optoelectronics, photonics, renewable energy, and medicine.
Lead sulfide/selenide quantum dots were considered as indispensable materials for the construction of the devices operating in the near-infrared spectral region. Recently, semiconductor nanoplatelets joined a family of nanomaterials. While colloidal semiconductor nanoplatelets emitting in the visible spectral range were studied in detail, much less attention was paid to their lead sulfide/selenide counterparts. The development of new approaches for the synthesis of near infrared-emitting nanoplatelets, study of their optical properties, and their interaction with other nanomaterials are important for their further application in optoelectronics.
Metal-halide perovskite nanocrystals became the most intensively studied nanomaterials last years. Due to their brilliant physical properties and feasible synthesis, they are considered the most promising material for solar cells, light-emitting diodes, photodetectors, etc. Doping is a versatile strategy to tune the optical and electrical properties of semiconductors. Doping the metal-halide perovskite nanocrystals may aim for the improvement of their optical properties and stability, as well as the achievement of fully new characteristics. In this regard, B-site cation doping opens numerous opportunities for the design of perovskite nanomaterials.
Carbon dots are a new class of easily accessible and environmentally friendly carbon nanomaterials. Carbon dots provide numerous ways to tune their optical properties by modification of synthetic approaches or surface functionalization with a great variety of molecules and/or chemical functional groups. The non-toxic nature of carbon dots combined with their high photoluminescence quantum yield is, in particular, promising for bio-applications. Moreover, carbon dots can be considered as versatile auxiliary components for optoelectronic devices. For instance, they were extensively applied to perovskite-based solar cells and light-emitting diodes. It was realized that carbon dots may influence charge carriers extraction and transport, promote perovskite crystallization, allow for efficient passivation, block ion migration, suppress hysteresis, enhance their environmental stability, and thus improve the performance of perovskite-based optoelectronic devices.
In this talk, recent research on the specified topics made in the PhysNano Department of ITMO University will be briefly discussed.