Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV24)
DOI: https://doi.org/10.29363/nanoge.hopv.2024.125
Publication date: 6th February 2024
The bandgap (Eg) tunability of metal halide perovskites over a wide spectral range from 1.2 eV to 3 eV through compositional engineering makes them particularly attractive for both single and multi-junction solar cells. Leveraging the extensive data available in the Perovskite Database1, we have performed a meta-analysis of over 40,000 sets of solar cell device metrics from peer-reviewed publications to elucidate the current state of broad Eg MHP semiconductor devices.
By comparing and contrasting intrinsic and optimization limitations across a wide range of Eg values from 1.2 eV to 3 eV, we find that while a wide variety of MHP absorbers have been developed, material quality across the Eg spectrum remains suboptimal. The most efficient solar cells are still achieved with structures close to the MAPbI3 archetype, due to a predominant optimization of the entire device to an absorber bandgap of 1.55 to 1.6 eV.
Our analysis reveals significant contributions of at least three primary factors to the degradation of device performance relative to the theoretical limit of the Shockley-Queisser model: 1) Mismatches in the energy levels of the selective transport materials for wide Eg MHPs. The losses at the material interfaces depend on the band offset and increase continuously with the energetic distance from the band energy for which the layer stack was optimized. 2) compromised optoelectronic quality of wide Eg MHP absorbers and 3) dynamic compositional heterogeneity induced by light-induced phase segregation phenomena. Above a bromide content of x=0.5, the device performance almost collapses. The contribution of light-induced phase segregation and decrease in PLQY occurring in this range are discussed as possible causes of this performance collapse.
Our meta-analysis underscores the significant progress made in MHP technology while highlighting the ongoing challenges in maximizing device performance across diverse Eg values. Insights from this study provide valuable guidance for future research efforts aimed at overcoming the identified limitations and realizing the full potential of MHP semiconductor devices.