Mitigating the interface defects influence on SnSe solar cells using optimized electron transport layer

Abstract

Abstract The field of photovoltaics relies heavily on compound semiconductors, particularly those based on selenium. However, challenges in maintaining stoichiometry and the scarcity of elements like Indium and Gallium hinder their widespread adoption. Tin monoselenide (SnSe) emerges as a promising alternative to silicon, thanks to its favorable properties, including a high absorption coefficient, suitable band gap, and excellent chemical stability. Additionally, SnSe exhibits superior thermal stability and can maintain efficiency under a wider range of operating conditions. Its unique crystal structure allows for enhanced charge carrier mobility, facilitating better performance in thin-film applications. These attributes collectively position SnSe as a highly competitive material in the pursuit of efficient and reliable solar energy solutions. Despite its potential, there is a lack of research on low-efficiency solar cells based on SnSe, highlighting the need for further exploration. Our study advocates for a theoretical investigation into the factors affecting SnSe-based solar cell efficiency, focusing on loss mechanisms like bulk and interface recombination. We propose an analytical model that examines various recombination mechanisms and their interactions to enhance efficiency. Experimental results validate our model, revealing the pivotal role of recombination mechanisms at both bulk and interface levels. Besides, the suggested model is used as a fitness function for the Multi Objective Particle Swarm Optimization (MOPSO) technique to identify the optimal combination of design parameters that produced the highest efficiency. The optimized design with In2O3 and MgZnO as Electron transport layer (ETL) materials surpasses current efficiency limitations and explore efficient Cd-free electron transport layer with suitable band alignment. Overall, our strategy by combining analytical model with optimization technique provides insights and solution for enhancing SnSe-based solar cell efficiency, to exceed 13%.

Keywords

• SnSe solar cells
• Recombination mechanisms
• Analytical model
• MOPSO optimization
• Charge transport layers