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Concept

Direct and indirect band gaps

Related publications (31)

Accurate and efficient band-gap predictions for metal halide perovskites at finite temperature

Alfredo Pasquarello, Patrick Gono, Thomas Bischoff, Haiyuan Wang

We develop a computationally efficient scheme to accurately determine finite-temperature band gaps for metal halide perovskites belonging to the class ABX(3) (A = Rb, Cs; B = Ge, Sn, Pb; and X = F, Cl, Br, I). First, an initial estimate of the band gap is ...

NATURE PORTFOLIO2022

Stoichiometry modulates the optoelectronic functionality of Zinc Phosphide (Zn3-xP2+x)

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Simon Robert Escobar Steinvall, Mahdi Zamani, Elias Zsolt Stutz, Rajrupa Paul, Mirjana Dimitrievska, Santhanu Panikar Ramanandan, Maria Chiara Spadaro, Mischa Samuel Flór, Diego Armando Sandoval Salaiza

Predictive synthesis–structure–property relationships are at the core of materials design for novel applications. In this regard, correlations between the compositional stoichiometry variations and functional properties are essential for enhancing the perf ...

2022

Nanoscale Growth Initiation as a Pathway to Improve the Earth-Abundant Absorber Zinc Phosphide

Anna Fontcuberta i Morral, Jean-Baptiste Leran, Simon Robert Escobar Steinvall, Mahdi Zamani, Rajrupa Paul, Mirjana Dimitrievska, Elias Zsolt Stutz

Growth approaches that limit the interface area between layers to nanoscale regions are emerging as a promising pathway to limit the interface defect formation due to mismatching lattice parameters or thermal expansion coefficient. Interfacial defect mitig ...

AMER CHEMICAL SOC2022

Optoelectronics based on the spin-valley physics of 2D materials

Juan Francisco Gonzalez Marin

Two-dimensional (2D) materials are atomically thin crystals with exceptional mechanical, electrical and optical properties. Their unique characteristics originating from quantum confinement in the vertical dimension have attracted a strong interest for sci ...

EPFL2022

Anionic character of the conduction band of sodium chloride

Klaus Kern, Abhishek Grewal

The alkali halides are ionic compounds. Each alkali atom donates an electron to a halogen atom, leading to ions with full shells. The valence band is mainly located on halogen atoms, while, in a traditional picture, the conduction band is mainly located on ...

Nature Portfolio2022

Single-Walled Black Phosphorus Nanotube as a NO(2 )Gas Sensor

Xiao Zhou

An ab initio density functional theory study on the candidacy of single-walled black phosphorus nanotubes (BPNTs) towards sensing several common toxic gas molecules (NH3, CO, NO, NO2, and SO2) was conducted. Various adsorption characteristics, including th ...

ELSEVIER2022

Electronic properties and ion migration of “in vacuo” lithiated nanoporous WO3:Mo thin films

Andreas Schueler, Josef Andreas Schuler, Luc Burnier, Jérémy Jacques Antonin Fleury

Electrochromic (EC) glazing helps manage daylight and solar heat gains in building, thereby allowing a reduction in energy consumption caused by heating, cooling, and artificial lighting. This study relates the optical and electronic properties of nanoporo ...

2022

Perovskite Solar Cells with Carbon-Based Electrodes - Quantification of Losses and Strategies to Overcome Them

Ulf Anders Hagfeldt, Bowen Yang, Jiajia Suo

Carbon-based electrodes represent a promising approach to improve stability and up-scalability of perovskite photovoltaics. The temperature at which these contacts are processed defines the absorber grain size of the perovskite solar cell: in cells with lo ...

WILEY-V C H VERLAG GMBH2022

Single molecule fluorescence and phosphorescence studies using a scanning tunneling microscope

Abhishek Grewal

This thesis investigates novel single-molecule luminescence phenomena at their inherent, sub-molecular length scale. The microscopic understanding of luminescence processes will be crucial for the continued improvement of organic optoelectronic and semicon ...

EPFL2022

Spectroscopic view of ultrafast charge carrier dynamics in single- and bilayer transition metal dichalcogenide semiconductors

Jens Christian Johannsen

The quasiparticle spectra of atomically thin semiconducting transition metal dichalcogenides (TMDCs) and their response to an ultrafast optical excitation critically depend on interactions with the underlying substrate. Here, we present a comparative time- ...

ELSEVIER2021

Band gaps of liquid water and hexagonal ice through advanced electronic-structure calculations

Alfredo Pasquarello, Igor Reshetnyak, Thomas Bischoff

The fundamental band gaps of liquid water and hexagonal ice are calculated through advanced electronicstructure methods. We compare specifically the performance of state-of-the-art GW calculations with nonempirical hybrid functionals. For the latter, we fi ...

AMER PHYSICAL SOC2021