Combining computational screening and experiment to discover "defect-tolerant" semiconductors for photovoltaics

Defect tolerance has emerged as a critical factor in assessing the potential of new solar absorber materials [1]. Here, we introduce our approach combining high-throughput computational screening and experiment to search for “defect-tolerant” absorbers. Specifically, in the screening we consider not only bulk properties (e.g., band gap) but also intrinsic defects and their role as potential nonradiative recombination centers, which enables identifying long carrier lifetime absorbers. For promising absorber candidates, we synthesize samples and perform optoelectronic characterization that can quantitatively assess the defect tolerance, including photoluminescence (PL) and carrier lifetime measurements. Using this approach, we have identified AM2P2 (A=Ca, Sr, Ba, M=Zn, Cd, Mg) Zintl phosphides as a new class of absorbers, with shallow intrinsic defects, bright PL, and carrier lifetime of up to 30 ns (>100 ns in latest samples) [2, 3, 4, 5, 6, 7]. Later, from a computational screening of all known phosphide compounds, we identify an unexpected earth-abundant absorber with exceptionally long carrier lifetime (~1000 ns) measured in both powder and single crystal samples, which will be reported in this presentation. These results demonstrate the effectiveness of the described approach in accelerating the discovery of “defect tolerant” solar absorbers.

[1] M. Hammer, Wolfgang Heiss et al., Nat. Rev. Mater. 10, 311 (2025).

[2] Z. Yuan, G. Hautier et al., Joule 8, 1412 (2024).

[3] S. Quadir, S. Bauers et al., Adv. Energy Mater. 14, 2402640 (2024).

[4] M. Hautzinger, S. Bauers et al., ACS Nano 19, 12345 (2025)

[5] A. Pike, G. Hautier et al., G. Hautier et al., Chem. Mater. 37, 4684 (2025).

[6] G. Kassa, J. Liu et al., arXiv preprint arXiv:2506.20829.

[7] G. Esparza, D. Fenning et al., arXiv preprint arXiv:2509.09803.