Influence of Guest/Host Morphology on Room Temperature Phosphorescence Properties of Pure Organic Doped Systems

Abstract

Guest/host phosphorescence materials have attracted much attention; traditionally, researchers have focused on the influence of the electronic properties and energy levels of the molecules on the phosphorescence activities. However, the effects of the morphology on the phosphorescence properties are ignored. Herein, three isoquinoline guests with different aliphatic rings and three hosts are selected to construct guest/host materials. Experimental results confirm that the guests are dispersed in the host in the form of clusters. More importantly, the morphologies of the guest/host directly affect the phosphorescence properties. In these systems, the guests have strong intermolecular interactions, which are beneficial to stabilize the triplet excitons; meanwhile, the hosts should have weak intermolecular interactions with easily changed morphology to accept the guest clusters, which synergistically ensure that the doped materials have excellent RTP properties. This is the first work focusing on the effect of molecular morphology on the phosphorescence characteristics of guest/host systems.

A Simple, Easy Preparation and Tunable Strategy for Preparing Organic Room-Temperature Phosphorescence

“…Doping RTP system using aromatic compounds as the host. (a) ref , (b) ref , (c) ref , (d) ref , (e) refs and , (f) ref , and (g) ref .…”

Host to regulate the T1–S1and T1–S0processes of guest excitons in doped systems to control the TADF and RTP emissions

“…S5, ESI†), which is in line with our previous works. 47–52 Therefore, three other doped materials with a guest–host molar ratio of 1 : 1000 are prepared as the research targets. However, it should be pointed out that, since the guest itself has strong fluorescence emission, different ratios of host–guest molar ratio have different effects on the fluorescence and phosphorescence intensity of the doped materials (Fig.…”

“…46–48 Moreover, some research results show that the host matrix can promote the transfer process of guest excitons between different energy levels. 49–54 Additionally, some doped materials that we have previously developed do also have the properties of emitting both TADF and RTP simultaneously. 28 Therefore, it is feasible to use different hosts to precisely modulate the ISC/RISC process of excitons, thereby ultimately regulating the luminescence phenomenon of doped materials.…”

Highly Efficient Heavy Atom Free Room Temperature Phosphorescence by Host-Guest Doping

“…So far, in order to increase intersystem crossing (ISC) rate and to suppress non-radiative transitions, many strategies have succeeded to achieve efficient organic RTP materials, such as host-guest doping, heavy-atom effects, intermolecular electronic coupling, supramolecular self-assembly, and so forth ( Yang et al, 2016 ; Chai et al, 2017 ; Cai et al, 2018 ; Yang et al, 2018 ; Shi et al, 2019 ; Alam et al, 2020 ; Lee et al, 2020 ; Li and Li, 2020 ). Among them, host-guest doping materials containing heavy atoms are an effective way to obtain efficient RTP by constructing a relatively rigid environment to restrain the nonradiative decay of the triplet state and promoting the ISC through the heavy-atom effect ( Bolton et al, 2011 ; Kabe and Adachi, 2017 ; Zhang et al, 2019a ; Zhang et al, 2019b ; Lei et al, 2020 ; Liu et al, 2021a ; Wang et al, 2021a ). For example, Bolton et al (2011) .…”