Active‐matrix organic light‐emitting diode using inverse‐staggered poly‐Si TFTs with a center‐offset gated structure

Abstract— A low‐cost active‐matrix backplane using non‐laser polycrystalline silicon (poly‐Si) having inverse‐staggered TFTs with amorphous‐silicon (a‐Si) n⁺ contacts has been developed. The thin‐film transistors (TFTs) have a center‐offset gated structure to reduce the leakage current without scarifying the ON‐currents. The leakage current of the center‐offset TFTs at Vg = ?10 V is two orders of magnitude lower than those of the non‐offset TFTs. The center‐offset length of the TFTs was 3 μm for both the switching and driving TFTs. A 2.2‐in. QQVGA (1 60 × 1 20) active‐matrix organic light‐emitting‐diode (AMOLED) display was demonstrated using conventional 2T + 1C pixel circuits.