The photo-induced ultrafast electron dynamics in both anatase and rutile TiO2 are investi-gated by using the Boltzmann transport equation with the explicit incorporation of electron-phonon scattering rates.All structural parameters required for dynamic simulations are ob-tained from ab initio calculations.The results show that although the longitudinal optical modes significantly affect the electron energy relaxation dynamics in both phases due to strong Fr?hlich-type couplings,the detailed relaxation mechanisms have obvious differences.In the case of a single band,the energy relaxation time in anatase is 24.0 fs,twice longer than 11.8 fs in rutile.This discrepancy is explained by the different diffusion distributions over the electronic Bloch states and different scattering contributions from acoustic modes in the two phases.As for the multiple-band situation involving the lowest six conduction bands,the predicted overall relaxation times are about 47 fs and 57 fs in anatase and rutile,respectively,very different from the case of the single band.The slower relaxation in rutile is attributed to the existence of multiple rate-controlled steps during the dynamic process.The present findings may be helpful to control the electron dynamics for designing efficient TiO2-based devices.

Man Lian;Yu-Chen Wang;Shiping Peng;Yi Zhao

State Key Laboratory of Physical Chemistry of Solid Surfaces,Fujian Provincial Key Lab of Theoretical and Computational Chemistry,and College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China

化学物理学报（英文版）

[1]Man Lian;Yu-Chen Wang;Shiping Peng;Yi Zhao-.Photo-Induced Ultrafast Electron Dynamics in Anatase and Rutile TiO2:Effects of Electron-Phonon Interaction)[J].化学物理学报（英文版）,2022(02):270-280

Photo,Induced,Ultrafast,Electron,Dynamics,Anatase,Rutile,TiO2,Effects,Phonon,Interaction,photo,induced,ultrafast,dynamics,both,anatase,rutile,are,investi,gated,by,using,Boltzmann,transport,equation,explicit,incorporation,phonon,scattering,rates,All,structural,parameters,required,simulations,tained,from,initio,calculations,results,show,that,although,longitudinal,optical,modes,significantly,affect,energy,relaxation,phases,due,strong,Fr,hlich,type,couplings,detailed,mechanisms,have,obvious,differences,case,single,fs,twice,longer,than,This,discrepancy,explained,different,diffusion,distributions,electronic,Bloch,states,contributions,acoustic,two,multiple,situation,involving,lowest,six,conduction,bands,predicted,overall,times,about,respectively,very,slower,attributed,existence,controlled,steps,during,process,present,findings,may,be,helpful,designing,efficient,devices

0.612346