The development of low-cost and environmentally friendly solar cell technologies has attracted significant attention as an alternative to traditional silicon-based devices. Carbon dots (CDs), owing to their tunable optical band gap, strong absorption in the visible spectrum, and excellent electron-donating properties, have emerged as promising sensitizers and interfacial modifiers in solar energy conversion systems. In this study, we present a systematic investigation of CDs/TiO2 heterojunction solar cells using both experimental findings reported in the literature and numerical simulations performed with SCAPS-1D. The structural configuration consists of a transparent conducting oxide (TCO), a TiO2 electron transport layer, a CDs absorber, and metallic contacts. Current density-voltage (J-V) characteristics were obtained to evaluate photovoltaic performance. The results demonstrate a short-circuit current density (Jsc) of approximately 16.518 mA/cm2, an open-circuit voltage (VOC) of about 0.772 V, a fill factor (FF) of 51.44 %, and a power conversion efficiency (PCE) approaching 6.56%. These values are consistent with experimental studies, validating the potential of CDs as efficient light harvesters. Furthermore, the role of interfacial defects and contact properties was analyzed, highlighting the importance of interface engineering to minimize recombination losses.
Cite this paper
Alsawi, A. , Alotaibi, H. , Alhumaidan, L. , Alshudukhi, M. , Aloufi, M. , Alnassar, M. , Alnawdali, S. , Alsaqabi, S. , Alharbi, S. , Alanbar, Y. , Alolayt, W. and Bouzgarrou, S. (2026). Simulation of the CDs/TiO2 Sample Behavior and Analysis of Its Curve Variations via SCAPS. Open Access Library Journal, 13, e14617. doi: http://dx.doi.org/10.4236/oalib.1114617.
Yadeta, T.F., Huang, K., Imae, T. and Tung, Y. (2022) Enhancement of Perov-skite Solar Cells by TiO2-Carbon Dot Electron Transport Film Layers. Nano-materials, 13, 186. https://doi.org/10.3390/nano13010186
Li, H., Shi, W., Huang, W., Yao, E., Han, J., Chen, Z., et al. (2017) Carbon Quantum Dots/TiOx Electron Transport Layer Boosts Efficiency of Planar Heterojunction Perovskite Solar Cells to 19%. Nano Letters, 17, 2328-2335. https://doi.org/10.1021/acs.nanolett.6b05177
Zhang, Q., Zhang, G., Sun, X., Yin, K. and Li, H. (2017) Improving the Power Conversion Efficiency of Car-bon Quantum Dot-Sensitized Solar Cells by Growing the Dots on a TiO2 Pho-toanode in Situ. Nanomaterials, 7, Article 130. https://doi.org/10.3390/nano7060130
Gao, N.X., Huang, L.B., Li, T.Y., Song, J.H., Hu, H.W. and Liu, Y. (2017) Application of Carbon Dots in Dye-Sensitized Solar Cells. Journal of Applied Polymer Science, 137, Article 48443.
Zhang, Q., Cao, J. and Li, H. (2015) CDS Sensitized TiO2 Photoanodes for Quantum Dot-Sensitized Solar Cells by Hydrothermal Assisted Chemical Bath Deposition and Post-Annealing Treatment. RSC Advances, 5, 107957-107963. https://doi.org/10.1039/c5ra18905e https://pubs.rsc.org/en/content/articlelanding/2015/ra/c5ra18905e
Saidarsan, A., Guruprasad, S., Malik, A., Basumatary, P. and Ghosh, D.S. (2025) A Critical Review of Unrealistic Results in SCAPS-1D Simula-tions: Causes, Practical Solutions and Roadmap Ahead. Solar Energy Materials and Solar Cells, 279, Article ID: 113230. https://doi.org/10.1016/j.solmat.2024.113230
Koen Decock, M.B., Nie-megeers, A., Verschraegen, J. and Degrave, S. (2025) SCAPS Manual Most Re-cent. https://users.elis.ugent.be/ELISgroups/solar/projects/scaps/SCAPS%20manual%20most%20recent.pdf
Xiang, P., Lv, F., Xiao, T., Jiang, L., Tan, X. and Shu, T. (2018) Improved Performance of Quasi-Solid-State Dye-Sensitized Solar Cells Based on Iodine-Doped TiO2 Spheres Photoanodes. Journal of Alloys and Compounds, 741, 1142-1147. https://doi.org/10.1016/j.jallcom.2018.01.220
Mandadapu, U., Thyaga-rajan, K. and Vedanayakam, S.V. (2017) Simulation and Analysis of Lead Based Perovskite Solar Cell Using Scaps-1D. Indian Journal of Science and Technology, 10, 1-8. https://doi.org/10.17485/ijst/2017/v10i11/110721
Bouzgarrou, S. (2025) Impact of Metal-Work Function and Temperature on the Performance of Schottky Barrier Diode Devices. Journal of Manufacturing Engineering, 20, 113-121. https://doi.org/10.37255/jme.v20i3pp113-121
Bouzgarrou, S. and Al-Shamari, H. (2024) Theoretical Study on Electrical Properties of N-AlGaAs Schottky Barrier Diodes in a Diverse Temperature Range. OALib, 11, 1-15. https://doi.org/10.4236/oalib.1112237
Czerniak-Reczulska, M., Niedzielska, A. and Jędrzejczak, A. (2015) Graphene as a Material for Solar Cells Applications. Advances in Materials Science, 15, 67-81. https://doi.org/10.1515/adms-2015-0024
Azevedo, J. (2013) Assemblage controlled de graphene et de nanotubes de Carbone par transfer de films de tensionactifs pour le photovoltaïque. Thesis, Université Paris Sud—Paris XI.
Okhay, O. and Tkach, A. (2024) A Comprehensive Review of the Use of Porous Graphene Frameworks for Various Types of Rechargeable Lithium Batteries. Journal of Energy Storage, 80, Article ID: 110336. https://doi.org/10.1016/j.est.2023.110336
Benetti, D., Jokar, E., Yu, C., Fathi, A., Zhao, H., Vomiero, A., et al. (2019) Hole-extraction and Photostability Enhancement in Highly Efficient Inverted Perovskite Solar Cells through Carbon Dot-Based Hybrid Material. Nano Energy, 62, 781-790.
Fatihi, D., Tseberlidis, G., Trifiletti, V., Binetti, S., Isotta, E., Scardi, P., et al. (2025) Enhanced Efficiency of CZTS Solar Cells with Reduced Graphene Oxide and Titanium Dioxide Layers: A SCAPS Simulation Study. ChemEngineer-ing, 9, Article 38. https://doi.org/10.3390/chemengineering9020038
