Related papers: Electronic Structure and Optical Properties of Tin…
We present the results of first-principles calculations on two possible terminations of the (001) surfaces of SrTiO3 (STO), BaTiO3 (BTO), and PbTiO3 (PTO) perovskite crystals. Atomic structure and the electronic configurations were…
Structural disorder is common in metal-halide perovskites and important for understanding the functional properties of these materials. First-principles methods can address structure variation on the atomistic scale, but they are often…
Solar to power conversion certified efficiencies of formamidinium lead iodide based single-junction perovskite solar cell is now 26%, all perovskite-perovskite tandem $\sim$28%, and the perovskite-silicon tandem solar cell is $\sim$34%…
In the search for stable lead (Pb) free perovskites, Vacancy ordered double perovskite (VODP), A$_2$BX$_6$ has emerged as a promising class of materials for solar harvesting owing to their nontoxicity, better stability, and unique…
X-ray diffraction studies showed that the structure of (Sr$_{1-x}$Pr$_x$)TiO$_3$ solid solutions at 300 K changes from the cubic $Pm3m$ to the tetragonal $I4/mcm$ with increasing $x$. The analysis of XANES and EXAFS spectra of the solid…
First principle FLAPW-GGA calculations have been performed with the purpose to understand the electronic properties for the newly synthesized tetragonal (space group P4/nmm) layered iron arsenide-oxide: Sr4Sc2Fe2As2O6 doped with titanium.…
This work presents a comprehensive investigation of the thermoelectric properties of bulk hybrid perovskites with the general formula MAxCs1-xSnI3 (0 < x < 1). A series of bulk samples were synthesized and systematically characterized to…
We theoretically investigate Sn(II) phosphates as optoelectronic materials using first principles calculations. We focus on known prototype materials Sn$_n$P$_2$O$_{5+n}$ (n=2, 3, 4, 5) and a previously unreported compound, SnP$_2$O$_6$…
Being one of the strongest materials, ternary TiSiN exhibits a very interesting family of binary transition metal nitride and silicide systems. A novel technique to fabricate morphologically fascinating nano and micro structures of TiSiN is…
New blends of simply synthesized quasi two-dimensional (quasi-2D) hydrophobic perovskite semiconductors, employed in high performance light emitting diodes (LEDs) which function due to excitonic energy transfer effects, are reported. These…
Nonequilibrium processes occurring in functional materials can significantly impact device efficiencies and are often difficult to characterize due to the broad range of length and time scales involved. In particular, mixed halide hybrid…
The few reported members of the antiperovskite structure class $Ae_3Pn_APn_B$ of alkaline earth ($Ae$ = Ca,Sr,Ba) pnictides ($Pn$ = N,P,As,Sb,Bi) compounds are all based on the B-site anion $Pn_B$=N. All fit can be categorized as narrow gap…
The full phonon dispersion relations of lead titanate and lead zirconate in the cubic perovskite structure are computed using first-principles variational density-functional perturbation theory, with ab initio pseudopotentials and a…
We study a newly predicted layered-ternary compound Ti4SiN3 in its {\alpha}- and {\beta}-phases. We calculate their mechanical, electronic and optical properties and then compare these with those of other compounds M4AX3 (M = V, Ti, Ta; A =…
Novel halide perovskites with improved stability and optoelectronic properties can be designed via composition engineering at cation and/or anion sites. Data-driven methods, especially high-throughput first principles computations and…
The spectacular performance of halide perovskites in optoelectronic devices is rooted in their tolerance to defects. Previous studies showed that defects in these materials generate shallow electronic states. However, how these shallow…
Hybrid perovskites with mixed organic cations such as methylammonium and formamidinium have attracted interest due to their improved stability and capability to tune their properties varying the composition. In this work we report on the…
Band structure of inorganic lead halide perovskites is substantially different from the band structure of group IV, III-V and II-VI semiconductors. However, the standard empirical tight-binding model with sp3d5s* basis gives nearly perfect…
We present a density-functional theory study addressing the energetics and electronic structure properties of isolated oxygen adatoms at the SrTiO3(001) surface. Together with a surface lattice oxygen atom, the adsorbate is found to form a…
It is now widely recognized that surface and interfacial defects exhibit distinct behavior compared to bulk defects in metal halide perovskites. However, the transition from bulk to surface behavior and the spatial extent of the surface's…