A family of donor–acceptor–donor (D–A–D) type near-infrared (NIR) fluorophores containing rigid nonplanar conjugated tetraphenylethene (TPE) moieties was designed and synthesized through Stille coupling reactions with electron-deficient [1,2,5]thiadiazolo[3,4-g]quinoxaline (QTD) or benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole (BBTD) as acceptors. The absorption, fluorescence, and electrochemical properties were studied. These compounds exhibited good aggregation-induced emission enhancement (AIEE) property, as a result of the twisted TPE units, which restrict the intramolecular rotation and reduce the π–π stacking. Photoluminescence of these chromophores ranges from 600 to 1100 nm, and their HOMO–LUMO gaps are between 1.85 and 1.50 eV. Non-doped organic light-emitting diodes (OLEDs) based on these fluorophores were made and exhibited EL emission spectra peaking from 706 to 864 nm. The external quantum efficiency (EQE) of these devices ranged from 0.89% to 0.20% and remained fairly constant over a range of current density of 100–300 mA cm–2. The device with the highest solid fluorescence efficiency emitter 1a shows the best performance with a maximum radiance of 2917 mW Sr–1 m–2 and EQE of 0.89%. A contrast between nondoped and doped OLEDs with these materials confirms that AIEE compounds are suitable for fabricate efficient nondoped NIR OLEDs.Keywords: AIEE; donor−acceptor; near infrared; OLEDs;

Graphene oxide (GO) was modified by surface grafting and the product P-GO exhibited a surprisingly good solubility in common solvents (as high as 1.8 mg mL−1 in DMF) without sonication and can be spin coated to form large single-layer sheets on a substrate. In contrast to GO, all-single-layer P-GO sheets are readily formed in solution, which are highly useful for separation from other multi-layer sheets and as precursors to all-single-layer graphene. The unique property of single-layer P-GO made it a promising functional material, such as hole-injecting buffer (HIB) material in organic light-emitting devices. The devices using P-GO as a hole-injecting buffer layer on the ITO electrode perform better than those with PEDOT:PSS.

Soluble, film-forming near-infrared arylene bisthienoimidazole dyes with a band gap of 1.2–1.3 eV are electrochromic and absorb strongly at the telecommunication wavelengths (1310 and 1550 nm) in the oxidized state.

Through efficient Förster resonance energy transfer, the near-infrared emission (850 nm) of a guest (weak near-infrared emitter)–host (strong deep-red emitter) system is greatly enhanced by excitation of the host molecule at 508 nm, in comparison with excitation of the guest molecule at 660 nm.

Graphene oxide (GO) was modified by surface grafting and the product P-GO exhibited a surprisingly good solubility in common solvents (as high as 1.8 mg mL−1 in DMF) without sonication and can be spin coated to form large single-layer sheets on a substrate. In contrast to GO, all-single-layer P-GO sheets are readily formed in solution, which are highly useful for separation from other multi-layer sheets and as precursors to all-single-layer graphene. The unique property of single-layer P-GO made it a promising functional material, such as hole-injecting buffer (HIB) material in organic light-emitting devices. The devices using P-GO as a hole-injecting buffer layer on the ITO electrode perform better than those with PEDOT:PSS.

Through efficient Förster resonance energy transfer, the near-infrared emission (850 nm) of a guest (weak near-infrared emitter)–host (strong deep-red emitter) system is greatly enhanced by excitation of the host molecule at 508 nm, in comparison with excitation of the guest molecule at 660 nm.