We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Specific capacitance of CoS encapsulated g-C<sub>3</sub>N<sub>4 </sub>core shell nanocomposite as extremely efficient counter electrode in quantum dots solar cells.
- Authors
Mahmoud, Sawsan A.; Mohamed, Fatma E.; El-Sadek, B. M.; Elsawy, M. M.; Bendary, Samar H.
- Abstract
In this context, the electrical conductivity and surface activity of cobalt sulphide (CoS) as counter electrode CE is improved by incorporating with graphitic carbon nitride (g-C3N4) to enhance the power conversion efficiency (PCE) of quantum dot sensitized solar cells (DSSCs). Core–shell nanocomposite CoS@g-C3N4 composed of CoS core encapsulated by graphitic carbon nitride shell in different weight ratios of CoS to constant ratio of g-C3N4 was synthesised. The prepared composites were assigned as 1:1 (CoS-1), 5:1 (CoS-5), 7:1(CoS-7), 9:1(CoS-9) and 11:1(CoS-11). The different prepared CoS@g-C3N4 nanocomposites were applied as counter electrodes (CEs) in QDSSCs based on TiO2 nanorod arrays with 84.37-nm length and 5.24-nm width as working electrode, cadmium sulphide (CdS) as quantum dots and polysulfide electrolyte. The results show that CoS-7 has superior efficiency with clear improvement in cell performance up to 10.15%, short current density Jsc of 19.5 mA/cm2, open circuit voltage Voc of 0.68 mV and fill factor (FF) of 0.78. The improved performance is attributed to the formation of synergistic heterojunction between g-C3N4 and CoS which facilitates a fast electron transfer at the interface between them; also, more photoelectrons could be produced due to the formation of carbon vacancies in g-C3N4 which made g-C3N4 to hold more excitable electrons and inhibit the recombination of photogenerated carriers. Matching the valence and conduction bands of CoS to those of g-C3N4 also catalyses collecting and mobility rate of the electrons and holes and decreases the recombination rate effectively. Cyclic voltammetry, impedance spectroscopy, the equivalent circuit, analysis of capacitance-frequency spectra, charge transfer spectra and charge recombination were also studied.
- Subjects
QUANTUM dots; SOLAR cells; SURFACE conductivity; CHARGE carriers; ELECTRIC conductivity; OPEN-circuit voltage; ION recombination
- Publication
Journal of Solid State Electrochemistry, 2021, Vol 25, Issue 8/9, p2345
- ISSN
1432-8488
- Publication type
Article
- DOI
10.1007/s10008-021-04992-0