Applied Surface Science, Vol.402, 336-343, 2017
A novel pi-conjugated Zn <- S -> Zn unit interface in the ZnS/Zn(S)(2)L inorganic/orgainc hybrids for significant photoelectric response
By using a novel Zn(S)(2)L complex (L=N-hexy1-3-{2-(4-(2,2':6',2"-terpyridin-4'-yl)pheny)ethenyl} carbazole) as a surface stabilizing agent, the self-assembled microspheres of Zn(S)(2)L-capped ZnS nanocrystals are obtained in a simple ethanol solvothermal process. Because of the strong IT character of the two terminal sulfur atoms (S1- valence state) in the Zn(S)(2)L complex, the Zn(S)(2)L complex could incorporate ZnS nanocrystals together by a homologous Zn <- S -> Zn)In unit interface. In the work, the homologous Zn <- S -> Zn unit interface is proposed to function as a pi-conjugated bridge for effective electron-transfer transition from Zn(S)(2)L moiety to ZnS nanocrystal to significantly improve the photoelectric response performance, such as the long lifetime of photogenerated charge carriers from 8 x 10(-8) s to 4 x 10(-5) s and the high recombination luminescence quantum efficiency (QE) up to 69%, which are confirmed by the systematically investigation with Raman spectra, XPS spectra, Uv-vis absorption spectra, photoluminescence (PL) spectra and transient photovoltage (TPV) technique. The ZnS/Zn(S)(2)L used as extra electron donor in organic/inorganic hybrid solar cell device could increase performance up to about 30%. (C) 2017 Elsevier B.V. All rights reserved.