Thermalization and relaxation mediated by phonon management in tin-lead perovskites
作者机构：Cavendish LaboratoryUniversity of Cambridge19 J.J.Thomson AvenueCambridge CB30HEUK
出 版 物：《Light(Science & Applications)》 (光(科学与应用(英文版))
年 卷 期：2023年第12卷第9期
页 面：1971-1981页
核心收录：
学科分类：08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学]
基 金：supported by the EPSRC(Grant EP/M005143/1)
主 题：alloy relaxation phonon
摘 要：Understanding and control of ultrafast non-equilibrium processes in semiconductors is key to making use of the full photon energy before relaxation,leading to new ways to break efficiency limits for solar energy *** this work,we demonstrate the observation and modulation of slow relaxation in uniformly mixed tin-lead perovskites(MASn_(x)Pb_(1-x)I_(3)and CsSn_(x)Pb_(1-x)I_(3)nanocrystals).Transient absorption measurements reveal that slow cooling mediated by a hot phonon bottleneck effect appears at carrier densities above~10^(18)cm^(−3)for tin-lead alloy nanocrystals,and tin addition is found to give rise to suppressed *** the alloy nanoparticles,the combination of a newly introduced high-energy band,screened Fröhlich interaction,suppressed Klemens decay and reduced thermal conductivity(acoustic phonon transport)with increased tin content contributes to the slowed *** inorganic nanocrystals where defect states couple strongly with carriers,sodium doping has been confirmed to benefit in maintaining hot carriers by decoupling them from deep defects,leading to a decreased energy-loss rate during thermalization and an enhanced hot phonon bottleneck *** slow cooling we observe uncovers the intrinsic photophysics of perovskite nanocrystals,with implications for photovoltaic applications where suppressed cooling could lead to hot-carrier solar cells.
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