关于举行印度科学教育与研究学院Angshuman Nag教授学术报告会的通知
报告题目：Optical Properties of Layered Hybrid Perovskites: Nano @ Bulk
报 告 人：Angshuman Nag教授（Indian Institute of Science Education and Research (IISER), Pune）
邀 请 人：夏志国 教授
报告时间：2022年9月23日（周五）下午16:30-18:30
报告地点： 腾讯会议 409-392-238
会议直播网址：https://meeting.tencent.com/dm/tMaxQL82NSnA
报告摘要：Hybrid perovskites like (C4H9NH3)2PbI4 have fascinating layered crystal structure with periodic nanoscale interfaces between the inorganic {PbI4}2- and organic C4H9NH3+ layers. Because of these interfaces, electron and hole are confined in atomically thin {PbI4}2- inorganic well layers. Therefore, these layered perovskites are considered as electronically 2D systems, irrespective of their crystallite sizes.1,2 Importantly, the crystal structure is flexible, allowing a number of combinations of different organic cations and inorganic anions. So a rational design of the nanoscale interfaces, and hence, tunable optoelectronic properties are feasible. For example, excitonic binding energy can be controlled over an order of magnitude from a few tens of meV to a few hundreds of meV, with simple variation of composition of organic cations. An appropriate choice of chiral organic cation can induce chirality in optoelectronic properties arising from the inorganic sublattice.3 Furthermore, one can introduce new intermolecular chemical interactions between organic cations, resulting into completely water stable low dimensional hybrid perovskite.4 In this talk, I will discuss about how controlling nanoscale interface between organic and inorganic layers can yield interesting optical, optoelectronic and chemical properties.5 But note that the nanoscale properties will be discussed using millimeter sized single crystals.
References:
1. Sheikh, T.; Shinde, A.; Mahamuni, S.; Nag, A. Possible Dual Bandgap in (C4H9NH3)2PbI4 2D Layered Perovskite: Single-Crystal and Exfoliated Few-Layer. ACS Energy Lett. 2018, 3, 2940.
2. Sheikh, T.; Nawale, V.; Pathoor, N.; Phadnis, C.; Chowdhury, A.; Nag, A. Molecular Intercalation and Electronic Two Dimensionality in Layered Hybrid Perovskites. Angew. Chem. Int. Ed. 2020, 59, 11653.
3. Sheikh, T.; Maqbool, S.; Rajput, P. R.; Mandal, P.; Nag, A. Effect of Chirality on the Optical Properties of Layered Hybrid Perovskite R- and S-a-methylbenzylammonium lead iodide. Chem. Commun. 2022, 58, 7650.
4. Sheikh, T.; Maqbool, S.; Mandal, P.; Nag, A. Introducing Intermolecular Cation-p Interactions for Water-Stable Low Dimensional Hybrid Lead Halide Perovskites. Angew. Chem. Int. Ed. 2021, 60,18265.
5. Nag, A. “Plenty of Room” at the Interface of Hybrid Metal Halide Perovskite Single Crystals. Nano Lett. 2021, 21, 8529.
报告人简介：Angshuman Nag副教授任职于印度科学教育与研究学院-普纳，化学系，硕士和博士学位分别在印度科学教育与研究学院古瓦哈提、班加罗尔获得，并曾在芝加哥大学从事博士后研究。Angshuman Nag博士长期从事半导体发光材料电子结构与发光性能研究，在钙钛矿发光材料，特别是近年来低维和无铅钙钛矿发光材料研究领域做出了重要成绩，发表了系列高水平研究论文。曾获得了2020年印度材料研究学会奖章，并担任了Nano Letters, Chemistry of Materials和 ChemistrySelect期刊的国际编委。
