Design and Performance of Small-Molecule Donors with Donor-π-Acceptor Architecture Toward Vacuum-Deposited Organic Photovoltaics Having Heretofore Highest Short-Circuit Current Density.

The development of high-performance organic photovoltaic materials is of crucial importance for the commercialization of organic solar cells (OSCs). Herein, two structurally simple donor-π-conjugated linker-acceptor (D-π-A)-configured small-molecule donors with methyl-substituted triphenylamine as D unit, 1,1-dicyanomethylene-3-indanone as A unit, and thiophene or furan as π-conjugated linker, named DTICPT and DTICPF, are developed. DTICPT and DTICPF are facilely prepared via a two-step synthetic process with simple procedures. DTICPF with a furan π-conjugated linker exhibits stronger and broader optical absorption, deeper highest occupied molecular orbital (HOMO) energy levels, and better charge transport, compared to its thiophene analog DTICPT. As a result, vacuum-deposited OSCs based on DTICPF: C70 show an impressive power conversion efficiency (PCE) of 9.36% (certified 9.15%) with short-circuit current density (Jsc) up to 17.49 mA cm-2 (certified 17.56 mA cm-2), which is the highest Jsc reported so far for vacuum-deposited OSCs. Besides, devices based on DTICPT: C70 and DTICPF: C70 exhibit excellent long-term stability under different aging conditions. This work offers important insights into the rational design of D-π-A configured small-molecule donors for high efficient and stable vacuum-deposited OSCs.

[One-stage repair of full-thickness skin defect at dorsal skin of middle phalanx fingers using artificial dermis combing with digital artery perforator fascial flaps].

OBJECTIVE: To explore clinical effects of the stageⅠrepair of full-thickness skin defect at dorsal skin of middle phalanx fingers using artificial dermis combing with digital artery perforator fascial flaps. METHODS: From January 2019 to May 2020, 21 patients(27 middle phalanx fingers)with full-thickness skin defect were repaired at stageⅠusing artificial dermis combing with digital artery perforator fascial flaps. All patients were emergency cases, and were accompanied by the exposure of bone tendon and the defects of periosteum and tendon membrane. Among patients, including 11 males and 10 females aged from 18 to 66 years old with an average age of (39.00±8.01) years old;9 index fingers, 10 middle fingers and 8 ring fingers;range of skin defect area ranged from (2.5 to 3.5) cm×(1.5 to 3.0) cm;range of exposed bone tendon area was (1.5 to 2.0) cm×(1.0 to 2.0) cm. The time from admission to hospital ranged from 1 to 6 h, operation time started from 3 to 8 h after injury. RESULTS: All patients were followed up from 6 to12 months with an average of (9.66±1.05) months. The wounds in 26 cases were completely healed at 4 to 6 weeks after operation. One finger has changed into wound infection with incompletely epithelialized dermis, and achieved wound healing at 8 weeks after dressing change. All fingers were plump with less scars. The healed wound surface was similar to the color and texture of the surrounding skin. These fingers have excellent wearability and flexibility. According to the upper limb function trial evaluation standard of Hand Surgery Society of Chinese Medical Association, the total score ranged from 72 to 100. 26 fingers got excellent result and 1 good. CONCLUSION: StageⅠrepair of full-thickness skin defect at dorsal skin of middle phalanx fingers using artificial dermis combing with digital artery perforator fascial flaps is easy to operate with less trauma. It has made satisfactory recovery of appearance and function of fingers. It could provide an effective surgical method for clinical treatment of full-thickness skin loss of fingers with tendon and bone exposure.