• Record EQE of 17% achieved in fully stretchable OLEDs via exciplex-enabled strategy.
• Stretchable exciplex-assisted phosphorescent layer enhances triplet harvesting and maintains stability under strain.
• MXene-contact stretchable electrodes provide efficient charge injection with tunable work function.
• Intrinsic spin-orbit coupling of phosphorescent emitter remains stable under 50% tensile strain.