Photoinduced Charge Transfer in Hybrid Systems of CuInS2 Nanocrystals and Conductive Polymer

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• 作者：Rany Miranti ; Yuliar Firdaus ; Eduard Fron ; Mark Van der Auweraer ; J眉rgen Parisi ; Holger Borchert
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：October 1, 2015
• 年：2015
• 卷：119
• 期：39
• 页码：22669-22680
• 全文大小：620K
• ISSN：1932-7455

文摘

Colloidal CuInS₂ nanocrystals are a promising alternative to toxic cadmium or lead chalcogenide nanocrystals that are widely studied as absorbing material in hybrid solar cells. Photovoltaic devices with colloidal CuInS₂ nanoparticles suffer, however, still from low performance. The present study focuses on a detailed investigation of charge transfer as an elemental process involved in the energy conversion process. Therefore, the excited state properties and the process of charge transfer in CuInS₂ (CIS) nanocrystal/polymer composites were studied by applying quasi-steady-state photoinduced absorption (PIA) and steady-state photoluminescence (PL) as well as time-resolved photoluminescence (PL) spectroscopy. The excited state dynamics of our systems was studied using time-correlated single photon counting. We examined two different composites, namely, CuInS₂ nanocrystals combined with either poly(3-hexylthiophene) (P3HT) or poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b鈥瞉dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT). Optical absorption and emission spectra of these hybrid material systems exhibit luminescence quenching and polaronic photoinduced absorption indicating photoinduced charge transfer. By systematic variations of the composition of the films, the material ratios favoring efficient charge transfer were determined.