Solar Cells
The world is in continuous quest for highly sustainable energy sources that meet the growing demand and provide an alternative to the different pollutant energy sources such as fossil fuels. In this context, highly efficient solar cells will be pivotal in different sectors, including space applications [1]. Perovskite-based solar cells have observed tremendous growth in the last decade, aiming at developing renewable energy sources due to various advantages, including ease in fabrication, direct bandgap, high absorption, high carrier mobility, cost-effectiveness, etc. The enhancement of power conversion efficiency (PCE) in addition to its sustainability and further easing of the fabrication process, are the main driving forces of ongoing research activity. In this context, graphene is particularly promising since it not only provides better charge collection but also helps to improve the sustainability and low-temperature fabrication of the perovskite cell. In recent times, perovskite solar cells in homojunction configuration have gained a lot of attention since they offer an additional benefit in terms of an in-built electric field inside the active layer, offering better charge separation, which significantly reduces the recombination losses. In collaboration with the University of Rome Tor Vergata, we proposed a homojunction perovskite solar cell with graphene-doped TiO2 as the electron transport layer. It has been found that 1% of graphene concentration in the TiO2-based electron transport layer produces an efficiency of 22.7% [2]. Moreover, it is noticed that, unlike intrinsic perovskite solar cells, the homojunction configuration offers a larger degree of freedom in establishing better band alignment with the charge transport layer [3]. Taking advantage of various beneficial features, with the collaborative group, we are currently developing a highly efficient perovskite solar cell, which has the potential to exceed the PCE by more than 25%.
References
[1] R. Verduci, V. Romano, G. Brunetti, N. Yaghoobi Nia, A. Di Carlo, G. D’Angelo, C. Ciminelli, ‘Solar energy in space applications: review and technology perspectives’, Adv Energy Mater, vol. 12, no.29, pp. 2200125, 2022. https://doi.org/10.1002/aenm.202200125.
[2] N. Saha, G. Brunetti, M. N Armenise, A. Di Carlo, C. Ciminelli ‘Modeling Highly Efficient Homojunction Perovskite Solar Cells with Graphene-TiO2 Nanocomposite as the Electron Transport Layer’, IEEE J Photovolt, vol. 13, no. 5, pp. 705-710, 2023. https://doi.org/10.1109/JPHOTOV.2023.3289574.
[3] N Saha, G Brunetti, C Ciminelli, ‘Effect of Doping Concentration and Band Offset on the Efficiency of Homojunction Perovskite Solar Cells’, in Proceedings of SIE 2023, C. Ciofi and E. Limiti, Eds., Cham: Springer Nature Switzerland pp.250-256, 2023. https://doi.org/10.1007/978-3-031-48711-8_30.