Improving CdSe Quantum Dot/Polymer Solar Cell Efficiency Through the Covalent Functionalization of Quantum Dots: Implications in the Device Recombination Kinetics

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• 作者：Josep Albero ; Paola Riente ; John N. Clifford ; Miquel A. Peric脿s ; Emilio Palomares
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：July 3, 2013
• 年：2013
• 卷：117
• 期：26
• 页码：13374-13381
• 全文大小：355K
• 年卷期：v.117,no.26(July 3, 2013)
• ISSN：1932-7455

文摘

Novel quantum dot capping ligands based on fullerene derivatives were attached through click-chemistry to the surface of semiconductor CdSe nanocrystals (C₇₀鈥揅dSe). Steady-state and time-correlated luminescence studies in solution show efficient quenching of the quantum dot (QD) emission in C₇₀鈥揅dSe. When this material was blended with the polymer poly-3-hexyl thiophene (P3HT) to fabricate bulk-heterojunction solar cells, P3HT/C₇₀鈥揅dSe devices doubled the light-to-energy conversion efficiency when compared to P3HT/Py鈥揅dSe reference devices prepared using pyridine as the capping agent. This is due to an increase in both photocurrent and fill factor showing the beneficial efficient effect of fullerene to improve light harvesting and charge transport in these devices. However, C₇₀ also appears to increase recombination in these devices as evidenced by both transient absorption spectroscopy and transient photovoltage measurements. This work also discusses the effects on the CdSe functionalization with C₇₀ over the device charge recombination kinetics that limit the efficiency in CdSe QDs/polymer solar cells.