Bayesian optimization based on a unified figure of merit for accelerated materials screening: A case study of halide perovskites

Abstract

The figure of merit is of crucial importance in materials design to search for candidates with optimal functionality. In the field of photovoltaics, the bandgap (E g ) is a well-recognized figure of merit for screening solar cell absorbers subject to the Shockley-Queisser limit. In this paper, the bandgap as the figure of merit is challenged since an ideal solar cell absorber requires multiple criteria such as stability, optical absorption, and carrier lifetime. Multiple criteria make the quantitative description of material candidates difficult and computationally time-consuming. Taking halide perovskites as an example, we combine thermodynamic stability (ΔH d ) and E g into a unified figure of merit and use Bayesian optimization (BO) to accelerate materials screening. We have found that, in comparison to an exhaustive search via multiple parameters, BO based on the unified figure of merit can screen optimal candidates (E g,PBE between 0.6-1.2 eV, ΔH d >−29 meV per atom) more efficiently. Therefore, the proposed method opens a viable route for the search of optimal solar cell absorbers from a large amount of material candidates with less computational cost.

New Lead Free Halide Double Perovskite Materials: Potential Substitutes Towards Green Technology and Stable Optoelectronic Application

“…In this paper we have tried to explore the experimentally synthesized small band gap halide double perovskites Cs2CuMCl6 (M=Sb, Bi) [22][23][24][25][26][27][28][29][30]. The nanocrystals of these halide doubled perovskites and other related materials have been experimentally reported.…”

Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb 2 XGaBr 6 (XNa, K)

“…12 In this regard, doubleperovskites such as Rb 2 NaGaBr 6 and Rb 2 KGaBr 6 have the potential to replace CH 3 NH 3 PbI 3 solar absorber material as they have direct band gaps in the required range. 18 This is further strengthened by the fact that Cs 2 AgBiX 6 , a lead-free and chemically stable halide double perovskite, has recently been shown to be an environment-friendly alternative to CH 3 NH 3 PbI 3 . 19 Since Rb 2 NaGaBr 6 and Rb 2 KGaBr 6 have only recently been examined in theoretical studies, not enough information about their electronic structure and optical properties is available in the literature.…”

“…19 Since Rb 2 NaGaBr 6 and Rb 2 KGaBr 6 have only recently been examined in theoretical studies, not enough information about their electronic structure and optical properties is available in the literature. 18,20 In addition to their potential for photovoltaic applications, Wang et al 21 have also proposed double perovskite Cs 2 AgBiBr 6 for photocatalytic hydrogen production in combination with reduced graphene oxide. It has been shown that the prepared material exhibits high stability for over 120 hours.…”

“…The CsPbX 3 (XCl, I and Br) perovskites have suitable band gaps as compared to CH 3 NH 3 PbX 3 , however, the replacement of CH 3 NH 3 + ion with Cs + ion does not lead to much stability 12 . In this regard, double‐perovskites such as Rb 2 NaGaBr 6 and Rb 2 KGaBr 6 have the potential to replace CH 3 NH 3 PbI 3 solar absorber material as they have direct band gaps in the required range 18 . This is further strengthened by the fact that Cs 2 AgBiX 6 , a lead‐free and chemically stable halide double perovskite, has recently been shown to be an environment‐friendly alternative to CH 3 NH 3 PbI 3 19 .…”

“…This is further strengthened by the fact that Cs 2 AgBiX 6 , a lead‐free and chemically stable halide double perovskite, has recently been shown to be an environment‐friendly alternative to CH 3 NH 3 PbI 3 19 . Since Rb 2 NaGaBr 6 and Rb 2 KGaBr 6 have only recently been examined in theoretical studies, not enough information about their electronic structure and optical properties is available in the literature 18,20 …”