Designing Hybrid Chiral Photonic Films with Circularly Polarized Room-Temperature Phosphorescence

Mingcong Xu; Xueyun Wu; Yang Yang; Chunhui Ma; Wei Li; Haipeng Yu; Zhijun Chen; Jian Li; Kai Zhang; Shouxin Liu

doi:10.1021/acsnano.0c02060

Designing Hybrid Chiral Photonic Films with Circularly Polarized Room-Temperature Phosphorescence

ACS Nano. 2020 Sep 22;14(9):11130-11139. doi: 10.1021/acsnano.0c02060. Epub 2020 Aug 26.

Authors

Mingcong Xu¹, Xueyun Wu¹, Yang Yang², Chunhui Ma¹, Wei Li¹, Haipeng Yu¹, Zhijun Chen¹, Jian Li¹, Kai Zhang², Shouxin Liu¹

Affiliations

¹ Key Laboratory of Bio-based Material Science and Technology of Ministry of Education, Northeast Forestry University, Harbin 150040, China.
² Wood Technology and Wood Chemistry, Department of Wood Technology and Wood-based Composites, University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany.

PMID: 32813496
DOI: 10.1021/acsnano.0c02060

Abstract

Circular polarized luminescence (CPL) is essential to chiral sciences and photonic technologies, but the achievement of circular polarized room-temperature phosphorescence (CPRTP) remains a great challenge due to the instability of triplet state excitons. Herein, we found that dual CPL and CPRTP were demonstrated by hybrid chiral photonic films designed by the coassembly of cellulose nanocrystals (CNCs), poly(vinyl alcohol) (PVA), and carbon dots (CDs). Tunable photonic band gaps were achieved by regulating the ratio of CNC/PVA in the hybrid films, leading to tunable CPL with invertible handedness, tunable wavelengths, and considerable dissymmetric factors (g_lum) up to -0.27. In particularly, triplet excitons produced by CDs were stable in the chiral photonic crystal environment, resulting in tunable right-handed CPRTP with long lifetimes up to 103 ms and large RTP dissymmetric factors (g_RTP) up to -0.47. Moreover, patterned films with multiple polarized features were demonstrated by a mold technique.

Keywords: carbon dots; cellulose nanocrystals; chiral photonic film; circularly polarized luminescence; room-temperature phosphorescence; triplet excitons.