»ã±¨±êÌâ (Title)£ºCarrier Generation and Transport in Novel Low-dimensional Organic Semiconductors £¨ÐÂÐÍÓлú°ëµ¼ÌåÖÐÔØÁ÷×Ó²úÉúºÍ´«Êä £©
»ã±¨ÈË (Speaker)£ºDr. Hai Wang, (Utrecht University, NL & Max Planck Institute for Polymer Research, DE)
»ã±¨¹¦·ò (Time)£º2025Äê2ÔÂ21ÈÕ(ÖÜÎå) 9:00-11:00
»ã±¨µØÖ· (Place)£ºÐ£±¾²¿ G313
Ô¼ÇëÈË (Inviter)£ºÂí¹úºê
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ÌáÒª: The conversion of light into electrical currents is a fundamental process underlying the operation of various optoelectronic devices, including photovoltaics and photodetectors. Understanding the underlying photophysics, e.g., the generation and transport of charge carriers in photoactive materials following photoexcitation, is crucial for improving the energy conversion efficiency of these devices. Layered two-dimensional (2D) materials are emerging building blocks for next-generation electronics and optoelectronics. Since the discovery of graphene, the family of 2D materials has expanded significantly. The recent emergence of conductive semiconducting organic layers (e.g., graphene nanostructures and metallated covalent organic frameworks) has further extended the 2D materials library and introduced new functionalities for applications. In this talk, I will first provide an overview of ultrafast THz spectroscopy and demonstrate its utility in characterizing electrical transport properties of charge carriers in low-dimensional materials in a contact-free manner?. I will then discuss recent work from our group on understanding charge generation and transport mechanisms in novel organic semiconductors, including: (1) Giant exciton effects and free carrier generation mechanisms in graphene nanoribbons???, (2) Band-like charge transport in covalent organic frameworks???, and the impact of dimensionality (1D vs. 2D) on charge transport properties?
References
1. Wenhao Zheng et al., Nat. Phys. 18, 544¨C550 (2022).
2. Alexander Tries et al., Nano Lett. 20, 2993¨C3002 (2020).
3. Guanzhao Wen et al., Hot Exciton Dissociation in Graphene Nanoribbons, (submitted).
4. Shuai Fu et al., J. Am. Chem. Soc. 144, 7489¨C7496 (2022).
5. Mingchao Wang et al., Nat. Mater. 22, 880¨C887 (2023).
6. Shuai Fu et al., Nat. Commun. 16, accepted (2025).
