The chemisorption energy is an integral aspect of surface chemistry, central to numerous fields such as catalysis, corrosion, and nanotechnology. Electronic-structure-based methods such as the Newns-Anderson model are therefore of great importance in guiding the engineering of material surfaces with optimal properties. However, existing methods are inadequate for interpreting complex, multi-metallic systems. Herein, we introduce a physics-based chemisorption model for alloyed transition metal surfaces employing primarily metald-band properties that accounts for perturbations in both the substrate and adsorbate electronic states upon interaction. Importantly, we show that adsorbate-induced changes in the adsorption site interact with its chemical environment leading to a second-order response in chemisorption energy with thed-filling of the neighboring atoms. We demonstrate the robustness of the model on a wide range of transition metal alloys with O, N, CH, and Li adsorbates yielding a mean absolute error of 0.13 eV versus density functional theory reference chemisorption energies.

Methylammonium lead halide $\left({\mathrm{MAPbI}}_3\right)$ perovskite has emerged as one of the frontier optoelectronic semiconductors. To avoid lead toxicity, the role of Sn substitution and Pb vacancy (Pb-$⊠)$ are addressed in regulating stability and solar cell efficiency of ${\mathrm{MAPb}}_{1-X-Y}{\mathrm{Sn}}_X{⊠}_Y{\mathrm{I}}_3$ perovskite using hybrid density functional theory (DFT). The role of spin-orbit coupling (SOC) and the electron's self-interaction error are examined carefully. We find to reduce the Pb content from pristine ${\mathrm{MAPbI}}_3$, Sn substitution has a more favorable thermodynamic stability than creating Pb-$⊠$. Moreover, on substituting Sn, due to strong $s\text{−}p$ and $p\text{−}p$ couplings, the lower parts of the conduction band gets shifted downwards, which results in the reduction of the band gap (direct). This further helps us to get a high optical absorption coefficient (redshifted) and maximum solar cell efficiency in ${\mathrm{MAPb}}_{1-X}{\mathrm{Sn}}_X{\mathrm{I}}_3$ for $0<X\le 0.5$.

Diamond and cubic boron nitride (c‐BN) are promising ultrawide‐bandgap semiconductors for next‐generation high‐power and high‐frequency devices. Enabling these devices needs better understanding of interface electronic structure. Here, we investigate the effects of interfacial bonding and antisite point defects on the formation of two‐dimensional (2D) carrier gases at (111) diamond/c‐BN interfaces using hybrid density functional theory. c‐BN can be B‐ or N‐terminated. For each termination type, we identify two distinct interfacial bonding configurations, where a B (or N) atom is bonded to either one or three C atoms, resulting in four bonding types. Our results show that electron‐deficient C−B and electron‐rich C−N interfacial bonds result in 2D hole gas and 2D electron gas, respectively. Configurations with B (or N) bonded to three C atoms exhibit three times higher carrier density (1.3310 ) than those bonded to one C atom (4.4410 ). Furthermore, ‐type and ‐type antisite defects can stabilize C−B and C−N bonded interfaces, respectively, while reducing carrier density. Nevertheless, the carrier density remains high () even with these defects. This work may guide the engineering of diamond/c‐BN interfaces with tunable carrier densities for ‐ or ‐type conduction.