Solution-processed OLEDs (SP-OLEDs) offer a cost-effective and attractive alternative vacuum-deposited devices (VD-OLEDs); however, historically, the performance of SP-OLEDs has lagged behind that of VD-OLEDs, which has impeded their adoption. To achieve comparably high external quantum efficiencies (EQE), judicious materials and device designs are required for SP-OLEDs. One design approach involves the utilization of thermally activated delayed fluorescence (TADF) emitters as materials harvest both singlet and triplet excitons to produce light owing to their small energy gap between the singlet and triplet excited states (ΔEST) that enable the upconversion of triplet excitons to emissive singlets via reverse intersystem crossing (RISC). Therefore, like phosphorescent OLEDs, TADF-OLEDs can achieve 100% internal quantum efficiency (IQE). Multiresonant TADF (MR-TADF) emitters, firstly reported by Hatakeyama et al., are narrowband emissive compounds, and so are particularly attractive for display applications. Their rigid structure and the short-range charge transfer (SRCT) character of their emissive S1 state are the origin for the narrowband emission and the moderately small DEST that enables TADF. However, their typically planar structure also makes these materials prone to aggregation-cased quenching (ACQ). Thus, MR-TADF OLEDs typically use the emitter at very low doping concentrations, which results in a narrow recombination zone that contributes to the severe efficiency roll-off in the devices. The incorporation of bulky substituents on the MR-TADF emitters has been demonstrated to be an effective strategy to mitigate against the aggregation. Zhang et al. encapsulated the MR-TADF core, DtBuCzB, with an ortho,ortho-diDtCzPh group within D-Cz-BN and an ortho-CzPh group in S-Cz-BN as a comparation (Figure ) as a strategy to mitigate aggregation. D-Cz-BN shows improved resistance to ACQ as the ΦPL decreased modestly from 98 to 90% as the doping concentration increased from 1 to 30 wt% in 3,3-bis(N-carbazolyl)-1,1'-biphenyl (mCBP) compared to that of S-Cz-BN (95 to 84%) and the naked MR-TADF core, DtBuCzB, (92 to 48%). The EQEmax of the OLEDs with D-Cz-BN exhibited less sensitivity to the doping concentration of the emitter, decreasing from 28.7 to 24.8% in comparison the devices with S-Cz-BN and DtBuCzB where the EQEmax decreased from 22.1 to 16.1% and 21.0 to 9.9%, respectively, as the doping concentration increased from 5 to 20 wt%. However, all devices (5 wt% emitter doping)