Trap-Assisted Charge Injection into Large Bandgap Polymer Semiconductors

Trap-Assisted Charge Injection into Large Bandgap Polymer Semiconductors

TitleTrap-Assisted Charge Injection into Large Bandgap Polymer Semiconductors
Publication TypeJournal Article
Year of Publication2019
AuthorsDongdong Wang, Michael Fina, Suhan Kim, Chunmei Zhang, Ting Zhang, Yonghong Deng, Kai Chen, Lijuan Liang, Samuel S Mao, Andrew M Minor, Gao Liu
JournalMaterials
Volume12
Issue15
Pagination2427
Date Published07/2019
Abstract

The trap-assisted charge injection in polyfluorene-poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) model systems with an Al or Al/LiF cathode is investigated. We find that inserting 1.3 nm LiF increases electron and hole injections simultaneously and the increase of holes is greater than electrons. The evolution of internal interfaces within polymer light-emitting diodes is observed by transmission electron microscopy, which reveals that the introduction of LiF improves the interface stability at both the cathode (cathode/polymer) and the anode (indium tin oxide (ITO)/PEDOT:PSS). Above-mentioned experimental results have been compared to the numerical simulations with a revised Davids model and potential physical mechanisms for the trap-assisted charge injection are discussed.

DOI10.3390/ma12152427
Short TitleMaterials
Refereed DesignationRefereed