Sustainable coconut shell charcoal counter electrodes for efficiency enhancement in CdS quantum dot solar cells
Journal article, 2025
The use of activated coconut shell charcoal (ACSC) was explored as a cost-effective and viable alternative to platinum (Pt) counter electrodes (CE) in CdS quantum dot–sensitized solar cells (QDSSCs). The photovoltaic performances of QDSSCs with newly fabricated ACSC CEs by spraying method and Pt CEs were evaluated using current density–voltage measurements under 100 mWcm−2 light illumination. While the QDSSC with a Pt CE showed an efficiency of 1.26%, the QDSSC with an ACSC CE, with an optimal thickness of 25 μm, corresponding to a spray time of 60 s, showed an efficiency of 2.93%, demonstrating a more than two-fold increase in the efficiency. The physicochemical parameters of ACSC CEs were analyzed using FTIR, Raman, X-ray diffraction, cyclic voltammetry (CV), and Tafel characterization. CV, Tafel, and electrochemical impedance (EIS) analysis confirmed the superior electrocatalytic activity of the ACSC CE compared to the Pt CE for QDSSCs. The efficiency enhancement can be attributed to the increased photocurrent density due to the superior electrocatalytic activity of ACSC, which promotes efficient polysulfide reduction at the electrolyte/counter electrode interface. The porous nature of ACSC provides an increased specific surface area, facilitating redox reactions and improving the interaction between the electrolyte and the counter electrode. Additionally, the enhanced charge transfer capabilities of the ACSC-based counter electrode contribute to efficient electron transport and reduced recombination losses. These properties collectively optimize the cell’s performance by ensuring effective energy conversion. Consequently, ACSC is emerging as a promising novel material for counter electrodes in QDSSCs.
CdS quantum dot–sensitized solar cells
Activated coconut shell charcoal
Efficiency enhancement
Counter electrodes
Author
M. A. K. L. Dissanayake
University of Peradeniya
National Institute of Fundamental Studies
A. K. Karunaratne
National Institute of Fundamental Studies
University of Peradeniya
G. K.R. Senadeera
National Institute of Fundamental Studies
Open University of Sri Lanka
T M W J Bandara
University of Peradeniya
G. R.A. Kumara
National Institute of Fundamental Studies
A. D.T. Medagedara
National Institute of Fundamental Studies
J. M.K.W. Kumari
National Institute of Fundamental Studies
Ingvar Albinsson
University of Gothenburg
Institution of physics at Gothenburg University
Bengt-Erik Mellander
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
University of Gothenburg
Maurizio Furlani
University of Gothenburg, Department of Physics
Nandu B. Chaure
Savitribai Phule Pune University
O. I. Olusola
Federal University of Technology Akure
Ionics
0947-7047 (ISSN) 18620760 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Chemical Sciences
Physical Sciences
DOI
10.1007/s11581-025-06118-2