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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Carbon Nanotubes for Quantum Dot Photovoltaics with Enhanced Light Management and Charge Transport

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Autor(es):
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Tazawa, Yujiro [1] ; Habisreutinger, Severin N. [2, 3] ; Zhang, Nanlin [1] ; Gregory, Daniel A. F. [1] ; Nagamine, Gabriel [4] ; Kesava, Sameer V. [2] ; Mazzotta, Giulio [2] ; Assender, Hazel E. [1] ; Riede, Moritz [2] ; Padilha, Lazaro A. [4] ; Nicholas, Robin J. [2] ; Watt, Andrew A. R. [1]
Número total de Autores: 12
Afiliação do(s) autor(es):
[1] Univ Oxford, Dept Mat, 16 Parks Rd, Oxford OX1 3PH - England
[2] Univ Oxford, Clarendon Lab, Dept Phys, Parks Rd, Oxford OX1 3PU - England
[3] Natl Renewable Energy Lab, Chem & Nanosci Ctr, 15013 Denver West Pkwy, Golden, CO 80401 - USA
[4] Univ Estadual Campinas, Inst Fis Gleb Wataghin, Rua Sergio Buarque de Holanda 777, BR-13083859 Campinas, SP - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: ACS PHOTONICS; v. 5, n. 12, p. 4854-4863, DEC 2018.
Citações Web of Science: 1
Resumo

Colloidal quantum dot (CQD)-based photo-voltaics are an emerging low-cost solar cell technology with power conversion efficiencies exceeding 10%, i.e., high enough to be interesting for commercialization. Well-controlled and understood charge carrier transport through the device stack is required to make the next step in efficiency improvements. In this paper, polymer-wrapped single-walled carbon nanotube (SWNT) films embedded in an insulating poly(methyl methacrylate) (PMMA) matrix and capped by a thermally evaporated Au electrode are investigated as a composite hole transport layer and optical spacer. Employing transient absorption spectroscopy we show that the SWNTs enhance the charge transfer rate from CQD to CQD, ZnO, or SWNT. In order to pinpoint the underlying mechanism for the improvement, we investigate the energetics of the junction by measuring the relative alignment of the band edges, using Kelvin probe and cyclic voltammetry. Measuring the external quantum efficiency and absorption we find that the improvement is not mainly from electronic improvements but from enhanced absorption of the CQD absorber. We demonstrate experimentally and theoretically, by employing a transfer-matrix model, that the transparent PMMA matrix acts as an optical spacer, which leads to an enhanced absorption in the absorber layer. With these electronic and optical enhancements, the efficiency of the PbS CQD solar cells improved from 4.0% to 6.0%. (AU)

Processo FAPESP: 13/16911-2 - Espectroscopia avançada em novos nanomateriais
Beneficiário:Lázaro Aurélio Padilha Junior
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores