在半导体聚合物中提高电光效率
Yong Cao1, Ian D Parker1, Gang Yu1
1UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, California 93117-3022, USA.
Nature
|April 19, 2018
概括
研究人员通过混合材料在聚合物发光二极管中实现了电效率与光效率的50%. 这一突破超出了强度约束激子的理论极限,表明激子的约束能量较弱.
科学领域:
- 材料科学
- 有机电子
- 光物理学
背景情况:
- 结合的聚合物表现出发光,这对于聚合物发光二极管 (PLED) 来说至关重要.
- 电效率 (QE) 与光效率 (PL) 相比,PLED的性能受到限制.
- 强键激子的EL:PL QE理论极限为25%,但弱键激子可以接近单位.
研究的目的:
- 研究提高PLED中的EL:PL QE比率的方法.
- 在聚合物中探索激子结合能和效率之间的关系.
- 确定PLED的理论效率极限是否可以超越.
主要方法:
- 使用与电子传输材料混合的合聚合物制造PLED.
- 优化材料混合以提高电子注入效率.
- 测量和比较电光和光发光的量子效率.
主要成果:
- 在开发的PLED中达到约50%的EL:PL QE比率.
- 这一比率显著超过强结单元和三元激子的 25% 理论极限.
- 结果表明激子结合能量较弱或单子结合状态形成的概率较高.
结论:
- 混合电子输送材料有效地提高了电子注入和PLED效率.
- 这些发现挑战了强结合激子作为这些PLED中主要激发状态的假设.
- 这项工作为设计高效的有机发光装置开辟了道路.
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