First-Principles Design of Tandem Solar Cell Absorbers in the AM2Pn2 Family via Alloying

Some compositions of the formula AM₂Pn₂ have recently been observed as promising solar absorbers through high-throughput computing such BaCd₂P₂ [1]. In this talk, I will discuss generating new candidate materials from a parent structure by isovalent substitutions (A= Ba, Sr, Ca, Yb, Eu, Mg, M=Mn, Mg, Cd, Zn, Pn= Bi, Sb, As, P). We explore the thermodynamic and electronic properties of these compounds to screen for those which may be suitable for the top junction of tandem solar photovoltaics. We find that in this family many of the materials are thermodynamically stable in the same crystal structure and have a wide range of computed bandgaps. To design materials for tandem solar cells, we explore alloying these materials and screen for optimal properties. I will discuss computational tools to screen for stable and desirable alloys in a high throughput fashion and suggest promising material candidates for tandem solar cells.<br/>[1] Yuan, Z., Dahliah, D., Hasan, M. R., Kassa, G., Pike, A., Quadir, S., Claes, R., Chandler, C., Xiong, Y., Kyveryga, V., Yox, P., Rignanese, G. M., Dabo, I., Zakutayev, A., Fenning, D. P., Reid, O. G., Bauers, S., Liu, J., Kovnir, K., & Hautier, G. (2024). Discovery of the Zintl-phosphide BaCd2P2 as a long carrier lifetime and stable solar absorber. Joule, 8(5), 1412–1429. https://doi.org/10.1016/j.joule.2024.02.017