Triple-junction tandem solar cells: structural and spectral optimization for improved current matching and efficiency

Materials for Renewable and Sustainable Energy https://doi.org/10.1007/s40243-024-00291-6 (2025) 14:13 ORIGINAL PAPER Triple-junction tandem solar cells: structural and spectral optimization for improved current matching and efficiency Hugo Rolando Sánchez Quispe1 · Prakash Kanjariya2 · Suhas Ballal3 · Anita Devi4 · Girish Chandra Sharma5 · Radhwan Abdul Kareem6 · K. Satyam Naidu7 · Marwea Al-hedrewy8,9 · Ashish Kumar10 · Asaithambi Perumal11 Received: 11 November 2024 / Accepted: 18 December 2024 © The Author(s) 2024 Abstract In this work, a triple-junction tandem solar cell (TSC) has been designed in order to increase the photovoltaic (PV) performance through utilizing maximum light photons. To create three junctions in this work three subcells have been designed and optimized at its best PV performance. The optimization of all the three subcells have been done through the various variations in the absorber layer like thickness and bulk defect density (BDD). It has been seen that best PV parameters in the top middle and bottom cell are maximum at high thickness and low BDD. For the designing of triple junction tandem configuration, two filtered spectrums (FS1 and FS2) have been calculated for the proper current matching in the three subcells. The optimized triple-junction TSC demonstrates significantly enhanced PV parameters, including high open-circuit voltage (VOC- 2.750), short-circuit current density (JSC- 16.45 mA/cm2), fill factor (FF- 83.40%), and power conversion efficiency (PCE- 37.74%). The strategy of using filtered spectrums and exact design optimization provides a potential road to the next generation of high-efficiency tandem solar cells, furthering the field of renewable energy solutions. Keywords Photovoltaic · SCAPS-1d · Tandem solar cell · Current matching · Filtered spectrum · Optimization Introduction In the modern era renewable energy resources are very dominant in the energy conversion [1]. Among all the renewable energy resources, solar energy is untapped energy which is utilized for the electricity conversion. Photovoltaic (PV) performance of single junction solar cells are limited Asaithambi Perumal ; 1 2 Escuela Superior Politécnica de Chimborazo (ESPOCH), Sede Orellana, El Coca 220202, Ecuador Department of Physics, Faculty of Science, Marwadi University Research Center, Marwadi University, Rajkot, Gujarat 360003, India 3 Department of Chemistry and Biochemistry, School of Sciences, JAIN (Deemed to be University), Bangalore, Karnataka, India 4 Department of Chemistry Chandigarh Engineering College, Chandigarh Group of Colleges Jhanjeri, Mohali, Punjab 140307, India according to the S-Q limit [2, 3]. To break that limit multijunction solar cells are designed by various researchers till date [4–6]. As per literatures, various double and triple junction tandem solar cells have been designed. 3JTSC provides several advancement in PV technology by breaking the efficiency limit which is predicted by S-Q [7, 8]. In typical single-junction cells, a significant amount of sunlight is either 5 Department of Applied Sciences-Chemistry, NIMS Institute of Engineering & Technology, NIMS University Rajasthan, Jaipur, India 6 Ahl Al Bayt University, Kerbala, Iraq 7 Department of Chemistry, Raghu Engineering College, Visakhapatnam, Andhra Pradesh 531162, India 8 College of Technical Engineering, The Islamic University, Najaf, Iraq 9 College of Technical Engineering, The Islamic University of Al Diwaniyah, Al Diwaniyah, Iraq 10 Division of Research and Development, Lovely Professional University, Phagwara, India 11 Faculty of Civil and Environmental Engineering, Jimma Institute of Technology, Jimma University, Po Box - 378, Jimma, Ethiopia 13 13 Page 2 of 8 wasting due to thermalisation or goes not absorbed through the cell [9, 10]. 3JTSC achieve higher power conversion efficiency (PCE), as each subcell absorbs a specific range of wavelengths, minimizing energy loss by stacking three cells with progressively narrower bandgaps [11]. The design of these multi-junction cells often incorporates perovskite materials due to their tunable bandgaps, high absorption, and relatively low-cost fabrication [9]. To design the 3JTSC, three subcells have been utilized, top, middle and bottom subcells according to its bandgaps. Wide bandgap materials whose bandgap (1.5-2 eV) are utilized for the designing of top cell whereas bottom and middle have lower bandgap ranges [12, 13]. This architecture is designed as top cell is illuminated by 1.5AMG spectrum of intensity 1000 W/m2 and middle is illuminated under filtered spectrum coming from top cell. However bottom cell is illuminated through the filtered spectrum passing from top and middle layers. The Shockley-Queisser (S-Q) limit, which defines the theoretical maximum efficiency of a single-junction solar cell under standard illumination conditions, is a critical benchmark in the field of photovoltaic research. In the manuscript, we have referenced the S-Q limit to contextualize the potential performance of single-junction cells. However, to surpass this limit, the use of tandem cells, such as triple-junction solar cells, becomes essential. Triple-junction cells are designed to capture a broader range of the solar spectrum by utilizing multiple absorber layers with different bandgaps. This configuration enables the cells to exceed the S-Q limit for single-junction devices, as each subcell absorbs a distinct portion of the spectrum more efficiently. The use of triple-junction cells is therefore justified as a strategy to achieve higher power conversion efficiencies beyond the theoretical limits of single-junction cells. Recently, lead-free perovskites are also utilized, which supports in the reduction of toxicity in the environment, present in the conventional perovskite based cells [14, 15]. In the place of conventional PVK, researchers are shifted their research trend towards the leadfree based single junction subcells for the designing of the tandem solar cells [16]. The evolution of multi-junction solar cells began with dual-junction devices, particularly employing III-V semiconductors such as gallium arsenide (GaAs) and indium gallium phosphide (InGaP), which achieved excellent efficiencies but had limits in scalability and cost [17, 18]. With the advent of PVK materials, which have adjustable bandgaps and outstanding absorption optical properties, research into tandem structures has advanced significantly. According to studies conducted by et al. (2018) and Yang et al. (2020), perovskite-based tandem cells can achieve efficiencies of more than 30% under ideal conditions, making them viable replacements to conventional silicon-based PV modules [19]. 3JTSCs usually employ a combination 13 Materials for Renewable and Sustainable Energy (2025) 14:13 of top, middle, and low-bandgap materials-based bottom cells to improve efficiency through effective spectrum splitting [20]. In particular, r (...truncated)