摘要： The two efficient non-doped blue emitters with hybridized local and charge transfer state namely, NDBNPIN and DBTPIN have been synthesised and characterised. These materials are employed as a host for green and red phosphorescent OLEDs. The white device based on DBTPIN:Ir(MDQ)2(acac) (4%) exhibit maximum external quantum efficiency (ηex) ?24.8%; current efficiency (ηc) ?57.1 cdA?1; power efficiency (ηp) ?64.8 lmW?1 with Commission Internationale de l’Eclairage (CIE:0.49, 0.40) than NDBNPIN:Ir(MDQ)2acac (4%) device [ηex ? 23.1%; ηc ?54.6 cd A?1; ηp? 60.0 lm W?1 with CIE (0.47, 0.42)]. Development of blue emitter is crucial in organic light emitting devices (OLEDs) to reduce power consumption effectively1. For an OLED with stable emission the current efficiency (CE) is proportional to external quantum efficiency (?ex): power efficiency (PE) is determined by CE and operating voltage (V) [PE = π CE/V]2–4. Iridium and platinum based phosphorescent complexes and TADF (thermally activated delayed fluorescent materials) exhibit high ?ex, however, suffered with short lifetime and roll-off efficiency and also the production cost of phosphorescent materials are unfavourable for practical applications5. Therefore, low driving voltage with high brightness become the major issue to achieve efficient OLEDs6. In OLEDs, balanced hole: electron recombination leads to formation of CT exciton (charge-transfer) which undergo decay directly or relaxes to LE (local exciton), thus, utilization of both CT exciton and LE provides efficient EL (electroluminescence). From 4-(dicyanomethylene)-2-methyl-6-[4-(dimethylaminostyryl)-4H-pyran] with CT state maximum efficiency have been harvested7–9. Donor–acceptor (D–A) compounds with low % CT leads to RISC (reverse intersystem crossing) process which results high singlet utilisation efficiency(?s), however, colour-purity is still poor due to broadened PL (photoluminescence) and EL (electroluminescence) spectra10–13. D-A architecture with high % LE state leads to higher efficiency because of maximum orbital overlap whereas high % CT provides low efficiency due to partial hole and electron overlap. However, because of small energy splitting (ΔES-T ≈ 0) CT state undergo RISC process 11,12. These issues are overcome, by employing D–A configured emissive materials with results in enhanced ηs HLCT emissive state: stabilised LE and CT states results in ηPL(photoluminance efficiency) and high ηs.. Thus, construction of D–A emitters with HLCT emissive state is novel strategy to design efficient blue emitters.