Charge transport in organic amorphous systems has been considered to occur by intermolecular hopping.However,it has been difficult to reveal even the intra-and intermolecular structures because of their amorphous natu...Charge transport in organic amorphous systems has been considered to occur by intermolecular hopping.However,it has been difficult to reveal even the intra-and intermolecular structures because of their amorphous nature.Therefore,the details of charge transport at the molecular level have not been clarified.Here,we investigate a detailed molecular-level insight into the charge transport in an amorphous film by the analysis of multiscale simulation.The charge mobility is normally described by a constant value but is found to be widely distributed with two orders of magnitude even in the 100 nm neat film.From the detailed analysis at the molecular level,it becomesclear that there are three types of charge traps;in addition to(1)the well-known traps due to the site energy difference,we found(2)traps caused by the distribution of molecular packings in the aggregate,and(3)those by charge hopping against the electric field.These traps are the origins of the widely distributed mobilities and the understanding of these traps is important to improve mobility.展开更多
基金supported by JSPS KAKENHI grant numbers:JP20H05840(Grant-in-Aid for Transformative Research Areas,“Dynamic Exciton”,H.K.)JSPS Core-to-Core Program:JPJSCCA20220004(H.K.)JST SPRING:JPMJSP2110(H.S.).
文摘Charge transport in organic amorphous systems has been considered to occur by intermolecular hopping.However,it has been difficult to reveal even the intra-and intermolecular structures because of their amorphous nature.Therefore,the details of charge transport at the molecular level have not been clarified.Here,we investigate a detailed molecular-level insight into the charge transport in an amorphous film by the analysis of multiscale simulation.The charge mobility is normally described by a constant value but is found to be widely distributed with two orders of magnitude even in the 100 nm neat film.From the detailed analysis at the molecular level,it becomesclear that there are three types of charge traps;in addition to(1)the well-known traps due to the site energy difference,we found(2)traps caused by the distribution of molecular packings in the aggregate,and(3)those by charge hopping against the electric field.These traps are the origins of the widely distributed mobilities and the understanding of these traps is important to improve mobility.
