Hydrogen bonds and space restriction promoting long-lived room-temperature phosphorescence and its application for white light-emitting diodes

Miao Fu; Liuquan Lin; Xin Wang; Xiaoming Yang

doi:10.1016/j.jcis.2023.02.040

Hydrogen bonds and space restriction promoting long-lived room-temperature phosphorescence and its application for white light-emitting diodes

J Colloid Interface Sci. 2023 Jun:639:78-86. doi: 10.1016/j.jcis.2023.02.040. Epub 2023 Feb 13.

Authors

Miao Fu¹, Liuquan Lin¹, Xin Wang¹, Xiaoming Yang²

Affiliations

¹ College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
² College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China. Electronic address: ming4444@swu.edu.cn.

PMID: 36804795
DOI: 10.1016/j.jcis.2023.02.040

Abstract

Achieving the long-lived and strong room-temperature phosphorescence (RTP) is challengeable but desirable, especially for the enhanced phosphorescence and metal-free nanomaterials. Herein, we initially synthesized the green-fluorescence carbon dots (pm-CDs), and further obtained the composite of pm-CDs@DCDA with a long RTP lifetime of 1.01 s through embedding pm-CDs in dicyandiamide (DCDA). And the bright and long-lived afterglow of pm-CDs@DCDA with 365 nm of UV light excitation was observed by the naked eyes for more than 17 s either emerging as the dry solid or in water. Importantly, the phosphorescence intensity and lifetime of pm-CDs@DCDA were remarkably promoted owing to the intermolecular hydrogen bonds and the rigid environment, hence facilitating the intersystem crossing (ISC) process and restricting the non-radiative transition of triplet excitons. Taking advantage of the superior solid-state luminescence of pm-CDs@DCDA, we further innovatively prepared the white light-emitting diodes (WLEDs) with the tunable color temperatures by regulating the mass of pm-CDs@DCDA coated on the chips. This proposed study originally employed DCDA as a matrix to separate and immobilize pm-CDs, which built up a new avenue to improve the RTP property and offered a promising application in WLEDs.

Keywords: Composite; Hydrogen bonds; Long-lived and enhanced phosphorescence; Space restriction; White light-emitting diodes.