Accelerated Screening of Ternary Chalcogenides for Potential Photovoltaic Applications

Abstract

Chalcogenides, which refer to chalcogen anions, have attracted considerable attention in multiple fields of applications, such as optoelectronics, thermoelectrics, transparent contacts, and thin-film transistors. In comparison to oxide counterparts, chalcogenides have demonstrated higher mobility and p-type dopability, owing to larger orbital overlaps between metal–X covalent chemical bondings and higher-energy valence bands derived by p-orbitals. Despite the potential of chalcogenides, the number of successfully synthesized compounds remains relatively low compared to that of oxides, suggesting the presence of numerous unexplored chalcogenides with fascinating physical characteristics. In this study, we implemented a systematic high-throughput screening process combined with first-principles calculations on ternary chalcogenides using 34 crystal structure prototypes. We generated a computational material database containing over 400,000 compounds by exploiting the ion-substitution approach at different atomic sites with elements in the periodic table. The thermodynamic stabilities of the candidates were validated using the chalcogenides included in the Open Quantum Materials Database. Moreover, we trained a model based on crystal graph convolutional neural networks to predict the thermodynamic stability of novel materials. Furthermore, we theoretically evaluated the electronic structures of the stable candidates using accurate hybrid functionals. A series of in-depth characteristics, including the carrier effective masses, electronic configuration, and photovoltaic conversion efficiency, was also investigated. Our work provides useful guidance for further experimental research in the synthesis and characterization of such chalcogenides as promising candidates, as well as charting the stability and optoelectronic performance of ternary chalcogenides.

Monolayer 1T-Ag6S2 with Excellent Thermoelectric Properties

“…This is due to the rise in carrier concentration, which leads to more electrons or holes that can move freely in the material. This phenomenon is also common in other 2D TE materials, , like SnSe 2 and Ag 2 S . Third, when the carrier concentration and temperature are fixed, the σ of the n-type system surpasses that of the p-type system.…”

“…Figure illustrates the variation of κ l with temperature, and the κ l of 1T-Ag 6 S 2 along the x ( y ) axis is as low as 0.33 (0.27) W/mK at 300 K. This result is notably lower compared to the majority of 1T phase TMD materials and typical high-performance TE materials, such as 1T-ZrS 2 (the κ l is 2.39 W/mK at 300 K), 1T-SnSe 2 (the κ l is 3.27 W/mK at 300 K), 1T-HfSe 2 (the κ l is 1.8 W/mK at 300 K), ,, Bi 2 Te 3 (the κ l is 1.5 W/mK at 300 K), Bi 2 TeSe 2 (the κ l is 0.81 W/mK at 300 K), , and so on (Table ). The remarkably low κ l of 1T-Ag 6 S 2 is primarily due to the acoustic softening caused by the substitution of Ag 6 clusters, which leads to a decrease in phonon group velocity and therefore significantly reduces its κ l . , …”

Band Alignment of Oxides by Learnable Structural-Descriptor-Aided Neural Network and Transfer Learning

“…Virtual screening based on machine learning is an efficient way to explore new materials with desired functions, where a surrogate model enables us to virtually predict material properties. − In particular, theoretical calculations can generate comparatively large data sets that are prerequisites for constructing accurate surrogate models. Previous studies have reported successful materials screening for various properties by machine learning in combination with theoretical calculations. − ,− …”

Tuning the optoelectronic properties of emerging solar absorbers through cation disorder engineering

“…1–3 These emerging solar absorbers are important not only for single-junction outdoor PVs, but also as the bottom- or top-cell for multi-junction devices, 4,5 devices to harvest energy from indoor lighting to more sustainably power Internet of Things electronics, 6,7 as well as building-integrated PVs and agrivoltaics. 8 As such, these materials have significant potential to fulfil energy harvesting requirements that are complementary to the capabilities of crystalline silicon PVs, and many of the compounds investigated are inorganic materials, including kesterites, 9–11 chalcopyrites, 12–14 chalcogenides, 15–17 chalcohalides 18–20 and metal–halide perovskites. 21–23 Historically, efforts at discovering these materials have focussed on the optical properties of the solar absorbers, namely bandgap and absorption coefficient.…”