Abstract
We introduce hybrid solar cells with an architecture consisting of an electrodeposited ZnO nanorod array (NRA) coated with a conformal thin layer (<50 nm) of organic polymer-fullerene blend and a quasi-conformal Ag top contact (Thin/NR). We have compared the performance of Thin/NR cells to conventional hybrid cells in which the same NRAs are completely filled with organic blend (Thick/NR). The Thin/NR design absorbs at least as much light as Thick/NR cells, while charge extraction is significantly enhanced due to the proximity of the electrodes, resulting in a higher current density per unit volume of blend and improved power conversion efficiency. The NRAs need not be periodic or aligned and hence can be made very simply.
Highlights
In recent years, organic photovoltaics have attracted great interest due to their low cost, easy processing, and suitability for inexpensive, flexible substrates
To overcome the limitations of the conventional hybrid design, we have studied a nanostructured cell in which quasi-conformal thin layers of P3HT:[6],6-phenyl-C61-butyric acid methyl ester (PCBM) blend and top contact are successively deposited on a ZnO nanorod array, yielding a cell with a threedimensional (3D) top surface
It is seen that the nanorods are approximately 800-nm long, being coated by a thin layer of P3HT:PCBM blend (
Summary
Organic photovoltaics have attracted great interest due to their low cost, easy processing, and suitability for inexpensive, flexible substrates. Bulk heterojunction (BHJ) devices incorporating an intimate mixture of electron-donating and electron-accepting organic semiconductors have been used to improve charge separation, allowing the manufacture of active layers of around 200 nm, which absorb a reasonable fraction of visible light (Figure 1a) [1,2,3,4] For these thicknesses, achieving suitable percolation pathways and phase separation simultaneously in the range of the exciton diffusion length (approximately 10 nm) is challenging, [5,6,7] so great effort has been invested into controlling the morphology of the blends by choosing appropriate solvents or by employing annealing treatments [8,9,10,11]. This is currently limiting the efficiencies obtained for BHJ cells incorporating inorganic nanorods, which in the best cases just approach the efficiencies obtained for standard fully organic bulk heterojunction cells having thinner active layers, despite the higher mobilities of the semiconducting nanorods [24,25]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
