Dynamic recombination of triplet excitons in polymer heterojunctions

• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（11）
• 所属期刊栏目: CONDENSED MATTER:ELECTRONIC STRUCTURE,ELECTRICAL,MAGNETIC,AND OPTICAL PROPERTIES
• 页码范围: 463-468
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab9c13

摘要

The dynamic recombination of two triplet excitons with opposite spins in the heterojunction structure has been in-vestigated using a nonadiabatic evolution method.We demonstrate that luminous composite states including the excited polaron and the biexciton can be formed efficiently via the triplet exciton-triplet exciton reaction in the heterojunction and therefore this reaction can enhance the electroluminescence efficiency considerably,which is consistent qualitatively with experimental observations.Meanwhile,we find that,although the heterojunctions are beneficial to the generation of luminescent particles,large band offset caused by the heterojunction structure is not helpful to improve the electrolumi-nescence efficiency.In addition,the mechanism of the triplet exciton-triplet exciton reaction in heterojunction is different from that of two similar coupling chains.Our results may deepen the understanding of the electroluminescence mechanism in polymer light-emitting devices.