Taweesak Sudyoadsuk

Interlayers are a pivotal component in high‐performance organic photovoltaics (OPVs), but their incorporation comes with increased fabrication complexity and manufacturing costs. Herein, codeposition of both the active layer and electron transport layer (ETL) is achieved by a single film‐casting step of a solution containing the polymer donor, small molecule acceptor, and a perylene diimide‐derivative as an additive. By tuning the solubility and surface energy, phase separation of the additive leads to a self‐formed organic ETL with favorable charge extraction and collection efficiencies. This additive engineering is utilized to simplify the fabrication of various bulk‐heterojunction systems based on Y‐series acceptors, realizing metal oxide‐free inverted OPVs. Specifically, cells with PM6:BTP‐eC9 and our self‐formed ETL exhibit power conversion efficiencies of 14%.

Herein, we report the synthesis and characterization of an efficient ambipolar charge-carrier-transporting deep-red fluorophore (TPECNz) based on a donor–acceptor–donor (D–A–D)-type molecule and its application as a non-doped emitter in an organic light-emitting diode (OLED). The fluorophore TPECNz contains naphtho[2,3-c][1,2,5]thiadiazole (Nz) as a strong acceptor unit symmetrically functionalized with N-(4-(1,2,2-triphenylvinyl)phenyl)carbazole as a donor and aggregation-induced emission (AIE) luminogen. The experimental (solvatochromic and emission in THF/water mixtures studies) and theoretical investigations prove that TPECNz retains cooperative hybridized local and charge transfer (HLCT) and weak AIE features. Thanks to its D–A–D-type structure with a proper twist angle between the D and A units, a strong electron deficiency of the Nz unit, and electron-donating and hole-transporting natures of carbazole, TPECNz exhibits a strong deep red emission (λ_em = 648 nm) with a high fluorescence quantum yield of 96%, outstanding thermal property (T_g = 236 °C), and ambipolar charge-carrier-transporting property with a decent balance of mobility of electrons (1.50 × 10⁻⁵ cm² V⁻¹ s⁻¹) and holes (4.42 × 10⁻⁶ cm² V⁻¹ s⁻¹). TPECNz is successfully employed as a non-doped emitter in an OLED which displays deep red electroluminescent emission peaked at 659 nm with CIE coordinates of (0.664, 0.335)), an EQE_max of 3.32% and exciton utilization efficiency (EUE) of 47%.

Herein, we report the synthesis and characterization of an efficient ambipolar charge-carrier-transporting deep-red fluorophore (TPECNz) based on donor-acceptor-donor (D-A-D) type molecule and its application as a non-doped emitter in an organic light-emitting diode (OLED). TPECNz contains naphtho[2,3-c][1,2,5]thiadiazole (Nz) as a strong acceptor unit symmetrically functionalized with N-(4-(1,2,2-triphenylvinyl)phenyl)-carbazole as a donor and aggregation-induced emission (AIE) luminogen. The experimental (solvatochromic and emission in THF-water mixture studies) and theoretical investigations prove that TPECNz retains cooperative hybridized local and charge transfer (HLCT) and AIE features. Thanks to its D-A-D type structure with a proper twist angle between D and A units, a strong electron deficiency of Nz unit, and electron donating and hole-transporting natures of carbazole, TPECNz exhibits a strong deep red emission (l_em = 648 nm) with a high fluorescence quantum yield of 96%, outstanding thermal property (T_g = 236 ^oC), and ambipolar charge-carrier-transporting property with a decent balance of mobility of electron (1.50 x 10^-5 cm² V^-1 s^-1) and hole (4.42 x 10^-6 cm² V^-1 s^-1). TPECNz is successfully employed as a non-doped emitter in OLED which displays deep red electroluminescent emission peaked at 659 nm with CIE coordinates of (0.664, 0.335)), an EQE_max of 3.32% and exciton utilization efficiency (EUE) of 47%.