A series of new D–D–π–A‐type organic dyes – CCTnA (n = 1–3), CCT3N and CCT2PA, bearing the 3‐(3′,6′‐di‐tert‐butylcarbazol‐N′‐yl)‐N‐dodecylcarbazol‐6‐yl system as an electron donor moiety (D–D) – were synthesized by convenient methods and successfully utilized as dye sensitizers for dye‐sensitized solar cells (DSSCs). The central π‐conjugated bridges were made of oligothiophene and oligothiophene‐phenylene units, whereas the acceptor groups were either cyanoacrylic acid or cyanoacrylamide. Detailed investigation into the relationship between the structures, spectral and electrochemical properties, and performances of the DSSCs is described. The DSSC devices performed remarkably well, with typical overall conversion efficiencies of 3.60–5.69 %, and optimal incident photon‐to‐current conversion efficiencies (IPCEs) exceeding 80 %. The devices containing oligothiophene bridging groups performed better than those with oligothiophene‐phenylene bridging groups. Of solar cells based on these dyes, the CCT3A‐based one gave a maximum IPCE value of 84 %, a short‐circuit photocurrent density (Jsc) of 11.31 mA cm–2, an open‐circuit voltage (Voc) of 0.71 V and a fill factor (FF) of 0.71, corresponding to an overall conversion efficiency (η) of 5.69 % (>96 % of that of the reference N719‐based cell, η = 5.92 %). This work suggests that the organic dyes based on donor moieties or donor molecular architectures of this type are promising candidates for improvement of the performances of DSSCs.

ARTICLE This journal isTo realize highly efficient bifunctional blue-light emitting and hole-transporting materials for OLEDs, a series of pyrene-and triphenylamine-peripheral functionalized carbazole dendrimers, namely G1PYR, G2PYR, G1TPA and G2TPA, were designed, synthesized and characterized. Especially, G2PYR having four pyrene units substituted on the 2 nd generation carbazole dendritic scaffold exhibited a strong blue emission with high T g amorphous and good film-forming properties. Simple structured blue OLED (λ EL = 463 nm) using G2PYR as emissive layer and Alq3-based green OLED (λ EL = 512 nm) using G2PYR as hole-transporting layer with high luminance efficiencies (η) and low turn-voltages (V on ) of 5.89 cd A -1 and 3.1 V, and 5.15 cd A -1 and 2.6 V were attained, respectively. Graphical AbstractSolution processed blue OLED using these molecules as an emissive layer show an excellent luminance efficiency of 5.89 cd A -1 (EQE = 6.81%) and a pure blue emission with CIE coordinates of (0.15, 0.16), while Alq3-based green OLEDs using these molecules as a hole-transporting layer display a high luminance efficiency of 6.10 cd A -1 (EQE = 1.51%), indicating they are promising bifunctional materials for high efficiency OLEDs with much simpler device architecture.