Constructing host-σ-guest structures to optimize the efficiency of non-doped solution-processed OLEDs. Issue 4 (5th January 2021)

• Record Type: Journal Article
• Authors: Liu, Dan; Zhang, Meng; Chen, Haowen; Ma, Daiyu; Tian, Wenwen; Sun, Kaiyong; Jiang, Wei; Sun, Yueming
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 4(2021)
• Page Start: 1221
• Page End: 1227
• Publication Date: 2021-01-05
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc04959j
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Non-doped solution-processed OLEDs based on emitters with host-σ-guest structures showed blue emission with CIE (0.18, 0.31), 24.9 cd A −1 current efficiency and 9.5 lm W −1 power efficiency. Abstract : Two novel host-σ-guest emitters based on a blue emissive thermally activated delayed fluorescence (TADF) unit were designed and synthesized. By grafting 4TCzBN onto common host materials, these neat films (4TCzBN- o -PhCz and 4TCzBN- o -mCP) emit strong fluorescence with 39.4% and 60.8% photoluminescence quantum yields (PLQYs), respectively. And the oxygen-bridge linked host can not only suppress the triplet exciton quenching between guest units, but also improve the carrier transport ability. Non-doped OLEDs based on emitters formed by a solution process exhibit a maximum external quantum efficiency (EQE) of 8.0%, 24.9 cd A −1 current efficiency (CE) and low efficiency roll off. These results indicate that the device performance can be improved by constructing a host-σ-guest structure with the introduction of an o-bridge linked bipolar host. The strategy proposed in this paper may provide inspiration for the design of more efficient blue solution-processable TADF emitters.