Fernando P. Sabino

Optical and fundamental band gaps disparity in transparent conducting oxides: new findings for the In2O3 and SnO2 systems

The optical band gap, extracted from absorption measurements, defines the figure of merit for transparent conducting oxides (TCOs). In many oxides, such as [Formula: see text] or [Formula: see text], inversion symmetry introduces a selection rule that blocks transitions from the valence-band maximum to the conduction-band minimum. This raises the absorption threshold and enlarges the optical gap relative to the fundamental band gap. Here, we present density-functional computations identifying two optical gaps, either of which can be detected, depending on the optical light intensity. Under strong illumination, weak transitions from [Formula: see text]-points near the valence-band maximum contribute significantly to the absorption spectrum and define an optical gap matching the fundamental gap. Low optical intensities by contrast give prominence to the large optical gap determined by the selection rule. While experimental conditions have favored observation of the former optical gap in [Formula: see text], in contrast, absorption measurements in [Formula: see text] have focused on the latter. Our findings explain the disparity between the optical and fundamental gaps in bixbyite [Formula: see text] and predict that, measured under low illumination, the optical gap for rutile [Formula: see text] will increase, from 3.60 eV to 4.34 eV.

Stability and accuracy control of k · p parameters

The

A comprehensive study of g-factors, elastic, structural and electronic properties of III-V semiconductors using hybrid-density functional theory

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Origin of and tuning the optical and fundamental band gaps in transparent conducting oxides: The case ofM2O3(M=Al,Ga,In)

method is a successful approach to obtain band structure, optical and transport properties of semiconductors, and it depends on external parameters that are obtained either from experiments, tight binding or ab initio calculations. Despite the widespread use of the

Role of atomic radius andd-states hybridization in the stability of the crystal structure ofM2O3(M=Al, Ga, In) oxides

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Electronic structure of layered quaternary chalcogenide materials for band-gap engineering: The example ofCs2MIIM3IVQ8

method, a systematic analysis of the stability and the accuracy of its parameters is not usual in the literature. In this work, we report a theoretical framework to determine the

Interplay between structure asymmetry, defect-induced localization, and spin-orbit interaction in Mn-doped quantum dots

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Stability and accuracy control of k center dot p parameters

parameters from state-of-the-art hybrid density functional theory including spin-orbit coupling, providing a calculation where the gap and spin-orbit energy splitting are in agreement with the experimental values. The accuracy of the set of parameters is enhanced by fitting over several directions at once, minimizing the overall deviation from the original data. This strategy allows us to systematically evaluate the stability, preserving the accuracy of the parameters, providing a tool to determine optimal parameters for specific ranges around the

Large disparity between optical and fundamental band gaps in layered In2Se3

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Azobenzene Adsorption on the MoS2(0001) Surface: A Density Functional Investigation within van der Waals Corrections

-point. To prove our concept, we investigate the zinc blende GaAs that shows results in excellent agreement with the most reliable data in the literature.