Dual‐Exciplex Architecture: A Universal Route to Color‐Tunable OLEDs

Abstract Color‐tunable organic light‐emitting diodes (OLEDs) hold great promise for next‐generation photonic applications, including intelligent lighting, advanced anti‐counterfeiting systems, and adaptive displays. In this study, an innovative design of color‐tunable OLEDs based on tricomponent dual‐exciplex systems is proposed. By co‐blending two donors (mCP and TCTA) with an acceptor (PO‐T2T), two distinct exciplexes, a high‐energy exciplex (mCP:PO‐T2T, host) and a low‐energy exciplex (TCTA:PO‐T2T, guest), are simultaneously generated. This unique architecture enables voltage‐regulated host‐to‐guest energy transfer: under low bias, efficient transfer leads to dominant guest emission, whereas at higher voltages the saturation of guest excited states suppresses energy transfer and enhances host emission. The design demonstrates broad architectural versatility, spanning from ternary co‐doping (D hos t:D guest :A) to simplified blended‐donor/acceptor bilayer (D host :D guest /A) and layered heterostructures (D host /D guest /A). Corresponding devices, T‐0.03 (mCP:TCTA:PO‐T2T = 0.97:0.03:1), B‐0.1 (mCP:10 wt.%TCTA/PO‐T2T), and L‐0.1 (mCP/0.1 nm TCTA/PO‐T2T), achieve CIE shifts of (0.04, 0.09), (0.06, 0.15), and (0.07, 0.14), respectively. Moreover, substituting TCTA with alternative donors (TAPC or TPD) further extends the color‐tuning range, yielding shifts up to (0.08, 0.22) for TAPC‐based and (0.14, 0.31) for TPD‐based systems. These findings establish the tricomponent dual‐exciplex approach as a universal and effective strategy for high‐performance, voltage‐tunable OLEDs.