Hot photocarrier dynamics in organic solar cells

Download
2015-07-01
Lane, P. A.
Cunningham, P. D.
Melinger, J. S.
Esentürk, Okan
Heilweil, E. J.
Photocurrent in an organic solar cell is generated by a charge transfer reaction between electron donors and acceptors. Charge transfer is expected to proceed from thermalized states, but this picture has been challenged by recent studies that have investigated the role of hot excitons. Here we show a direct link between excess excitation energy and photocarrier mobility. Charge transfer from excited donor molecules generates hot photocarriers with excess energy coming from the offset between the lowest unoccupied molecular orbital of the donor and that of the acceptor. Hot photocarriers manifest themselves through a short-lived spike in terahertz photoconductivity that decays on a picosecond timescale as carriers thermalize. Different dynamics are observed when exciting the acceptor at its absorption edge to a thermalized state. Charge transfer in this case generates thermalized carriers described by terahertz photoconductivity dynamics consisting of an instrument-limited rise to a long-lived signal.
NATURE COMMUNICATIONS

Suggestions

Effect of Laser Parameters and Post-Texturing Treatments on the Optical and Electrical Properties of Laser Textured c-Si Wafers
RADFAR, Behrad; ES, FIRAT; NASSER, Hisham; AKDEMİR, Ozan; Bek, Alpan; Turan, Raşit (2018-03-21)
Surface plays a crucial role in the performance of crystalline silicon (cSi) based solar cells as it affects both electrical and optical properties. To minimize reflection from the flat surface and thus improve light trapping, the cSi wafers must be textured. For mono-cSi cells, anisotropic alkaline etchants are commonly utilized to create pyramids on the surface. However, this method is not viable for multi-crystalline silicon (mc-Si) wafers due to the presence of different and random crystallographic orie...
Photovoltaic and photophysical properties of a novel bis-3-hexylthiophelle substituted quinoxaline derivative
GÜNEŞ, Serap; Baran, Derya; Günbaş, Emrullah Görkem; Oezyurt, Funda; Fuchsbauer, Anita; Sariciftci, Niyazi Serdar; Toppare, Levent Kamil (Elsevier BV, 2008-09-01)
We report on the photophysical properties and photovoltaic performance of a polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline(PHTQ) as an electron donor in bulk heterojunction Solar Cells blended with the acceptor 1-(3-met hoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerence (PCBM). Devices were composed of PHTQ and varying amounts of PCBM (1:1, 1:2, 1:3, 1:4 w-w ratio). The components were spin cast from ortho-dichlorobenzene (ODCB) and characterized by mea...
Optical and electrical design guidelines for ZnO/CdS nanorod-based CdTe solar cells
Özcan, Can; Turkay, Deniz; Yerci, Selçuk (2019-04-15)
An alternative structure to planar CdTe solar cells is realized by coating ZnO/CdS nanorods (NRs) with a CdTe layer. These structures are expected to achieve high-powered conversion efficiencies through enhanced light absorption and charge carrier collection. ZnO NR-based CdTe solar cell efficiencies; however, they have remained well below their planar counterparts, thus hindering NRs in CdTe solar cells' advantages. Here, we analyze the light trapping and carrier collection efficiencies in two types of ZnO...
Production of flexible polymeric photoanodes using binder-free electrophoretic deposition and compression for dye-sensitized solar cells
Kocaoglu, Bahadir Can; Özenbaş, Ahmet Macit (2015-04-29)
Electrophoretic deposition (EPD) of titania nanoparticles have been utilized in order to form the nanoporous photoanodes of dye-sensitized solar cells (DSSCs) on flexible polymeric (PEN/PET) substrates. Highly uniform, adherent nanoporous thick films were produced by uniformly dispersing the titania nanoparticles in alcoholic suspensions without any binders. Suspension performances of each type of isopropanol based mixtures have been examined. Additionally, the effect of acetylacetone addition in suspension...
Enhancement in Oxygen Reduction Reaction Activity of Nitrogen-Doped Carbon Nanostructures in Acidic Media through Chloride-Ion Exposure
Jain, Deeksha; Mamtani, Kuldeep; Gustin, Vance; Gunduz, Seval; Çelik, Gökhan; Waluyo, Iradwikanari; Hunt, Adrian; Co, Anne C.; Ozkan, Umit S. (2018-07-11)
Nitrogen-doped carbon nanostructures (CNx) are promising cathode materials as catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte membrane (PEM) fuel cells. Incorporation of chlorine into CNx catalysts using a facile methodology can lead to a significant improvement in the ORR activity in acidic media, as confirmed by electrochemical half-cell measurements. The chlorine-containing CNx catalyst (CNx-Cl) is synthesized by soaking CNx powder in 0.3 M HCl. The analysis of near-edge X-ray ab...
Citation Formats
P. A. Lane, P. D. Cunningham, J. S. Melinger, O. Esentürk, and E. J. Heilweil, “Hot photocarrier dynamics in organic solar cells,” NATURE COMMUNICATIONS, pp. 0–0, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/41054.