Imaging Excited-State Dynamics in Two-Dimensional Semiconductors with Emerging Ultrafast Measurement Techniques

作     者：Joshua Reding Wei Zhang Jeremy Allam 

作者机构：Advanced Technology InstituteUniversity of SurreyGuildford GU27XHUnited Kingdom 

出 版 物：《Accounts of Materials Research》 (材料研究述评（英文）)

年 卷 期：2021年第2卷第2期

页      面：75-85页

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：Doctoral College of University of Surrey U.S. Air Force, USAF 

主　　题：properties. dynamics. splitting 

摘      要：CONSPECTUS:Two-dimensional halide perovskites(HPs)and monolayer transition metal dichalcogenides(TMDs)are two families of direct band gap semiconductors of particular interest for their unique structural and optoelectronic *** materials confine the motion of charge carriers to a single plane which increases the exciton binding energy,increases the stability of multibody particles,and decreases *** great progress in recent years,the widespread understanding of fundamental properties of these materials is limited by a number of remaining issues including(i)the effects of Rashba splitting and intravalley dynamics on recombination lifetimes;(ii)the effects of passivation of photoinduced and substrate-induced defects on trap state recombination(iii)the contribution of lattice variations and phase transitions on material *** properties influence the material and electronic dynamics on time scales in the range of femtoseconds to nanoseconds,and as such,they require equally fast measurements in order to be *** this perspective,three particular ultrafast pump−probe measurement techniques are highlighted for their ability to provide crucial insights into these unresolved ***-resolved circular dichroism spectroscopy(TRCDS)uses circularly polarized beams to selectively populate and interrogate carriers in spin split valleys,investigate Rashba splitting,and explore valley *** have been mixed results showing Rashba splitting using TRCDS to study pure 2D HPs,though it has successfully shown the splitting in quasi-2D perovskites with an even number of layers and HPs using chiral organic *** monolayer TMDs,it has been used extensively to study spin selective valley dynamics,trion and biexciton dynamics,and now the focus turns to investigating Janus ***-resolved photoemission microscopy uses an ionizing probe beam to eject electrons which are then measured to map defects caused by photoexcitation,subst