Organic light-emitting diodes (OLEDs) are now commonplace in displays in mobile phones, smartwatches and televisions and have made inroads in the solid-state lighting and automotive markets. Most OLEDs are fabricated using a vacuum deposition technology that employs a complicated multilayered device architecture that results in high production costs. An alternative strategy would be to fabricate the OLEDs using lower-cost solution-processing techniques such as ink-jet printing, which also would provide a much simpler route to the production of large-area displays. To achieve comparable performance metrics as vacuumdeposited devices, the key requirement for the solution-processed (SP) OLEDs is the availability of high-performance solution-processable emitter materials. Thermally activated delayed fluorescence (TADF) materials have attracted much attention over the last decade as a replacement emitter materials for noble metal-based phosphorescent complexes in OLEDs as they are less expensive and do not incorporate scarce platinoid metals yet are equally capable of harvesting up to 100% of the excitons to produce light. Although vacuum-deposited OLEDs with small molecule TADF emitters have shown outstanding efficiencies in devices across the visible spectrum, these compounds tend to crystallize and thus are not ideal for solution-processed film formation. Macromolecules, such as dendrimers or polymers, on the other hand are perfect candidates for SP-OLEDs because of their superior film-forming ability, excellent thermal and morphological stability, and high affinity for substrates. Significant progress has been made in the development of green and blue solution-processable TADF materials, and their corresponding SP-OLEDs exhibit outstanding maximum external quantum efficiency (EQEmax) of over 20%. Despite these achievements, there is presently a dearth of examples of efficient solutionprocessable red TADF emitters where their photoluminescence quantum yield is frequently much lower than for green and blue because of the lower radiative rate constant, kr, and higher non-radiative rate constant, knr, as a result of the energy gap law. So far, there are only a few reports of relatively efficient red TADF emitters for SP-OLEDs (Figure ). Zhang et al. reported an orange-red emitter 4t-BuCzTTR by using thianthrene 5,5,10,10-tetraoxide as the acceptor, 3,6-di-tert-butyl-9H-carbazole (tCz) as the donor and the resulting SP-OLEDs emitted at lEL= 592 nm and showed an EQEmax of 6.2%, which dropped to around ~4.0% at 1000 cd m -2 (EQE1000). A deep red wedge-shaped organic fluorophore, 2TPA-PPDC, was reported by Zhang et al., whose SP-OLEDs emitted at lEL= 670 nm and showed an EQEmax of 3.2%. A similar red emitter, DDTPACz-DCPP, containing carbazole donors that are additionally decorated with two TPA units was reported by Wang et al. The solutionprocessed devices with DDTPACz-DCPP showed EQEmax/EQE1000 of 13.6/~4.0% at λEL of 646 nm. Zeng et al. reported a SP-OLED containing the orange-red emitter NAI_R3 that contains an extended donor moiety and uses tert-butylbenzene groups to improve solubility, which emitted at lEL= 622 nm and showed an EQEmax of 22.5%, but the device also showed a significant efficiency roll-off with an EQE1000 of 3.4%. ) using two PXZs as donor moieties. SP-OLEDs with oDBBPZ-DPXZ emitted at lEL= 612 nm, and showed an EQEmax of 18.5%; however, efficiency roll-off was severe (EQE1000=~3.0%). This survey of the state-of-the-art in red TADF SP-OLEDs reveals that BP can be used effectively in red emitter design due to its rigid, large p-conjugated system. However, the efficiency of SP-OLEDs using BP-based red emitters still lags behind vacuum-deposited red TADF OLEDs with emitters containing the BP moiety, especially at high luminance (Figure ). Here, we address this issue by employing this rigid BP core as the acceptor and strategically introducing two different donor dendrons, GCz and DPACz at different positions about the acceptor. We thus report the development of four orange-red TADF dendrimers: