Nonrad: Computing nonradiative capture coefficients from first principles

Turiansky, Mark E.; Alkauskas, Audrius; Engel, Manuel; Kresse, Georg; Wickramaratne, Darshana; Shen, Julie; Dreyer, Cyrus E.; Walle, Chris G. Van de

doi:10.1016/j.cpc.2021.108056

Cited by 68 publications

(58 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1e, with the charge capture transition occurring between the metastable defects D * q → D * q±1 , prior to de-excitation and charge capture back to D q . While certainly possible, to our knowledge a defect centre exhibiting this behaviour has not been previously reported in the literature, which may be attributed to the recency of advancements in atomistic modelling of non-radiative carrier recombination [4][5][6]8,28 and our understanding of the importance of metastable structures in these processes. 9,15-17 Interestingly, we note that an analogous hot-electron capture mechanism was however invoked to explain the puzzling experimental observations of charge capture behaviour for negative-U DX centres in Al x Ga 1-x As in the 1980s.…”

Section: Capture Into Metastable Defectsmentioning

confidence: 89%

“…Anharmonic carrier capture coefficients were calculated using CarrierCapture.jl , 5 with electronphonon coupling matrix elements determined using the method outlined in Ref. 6. In-depth details of the computational implementation are provided in Ref.…”

Section: Methodsmentioning

confidence: 99%

“…By successively capturing electrons and holes through non-radiative (vibrational) processes, these defect levels allow excited charge carriers to recombine across the gap, reducing the open-circuit voltage in solar cells and the quantum efficiencies of light-emitting diodes for example. 1 Recent advances in both theory and computation have rendered possible the explicit prediction of defect recombination activity, [4][5][6][7][8][9] allowing for the ab initio identification of such 'killer' traps. The synergistic combination of theoretical methods and experimental characterisation has allowed for rapid improvements in photoconversion efficiencies for emerging inorganic PV materials.…”

Section: Introductionmentioning

confidence: 99%

“…Fig 6. Electron and hole capture cross-section (σ n and σ p ) as functions of temperature T for the Te i (+ ( * ) /0 ( * ) ) charge transition levels in CdTe.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Impact of metastable defect structures on carrier recombination in solar cells

Kavanagh,

Scanlon,

Walsh

et al. 2022

Preprint

View full text Add to dashboard Cite

The efficiency of a solar cell is often limited by electron-hole recombination mediated by defect states within the band gap of the photovoltaic (PV) semiconductor. The Shockley-Read-Hall (SRH) model considers a static trap that can successively capture electrons and holes. In reality however, true trap levels vary with both the defect charge state and local structure. Here we consider the role of metastable structural configurations in capturing electrons and holes, taking the tellurium interstitial in CdTe as an illustrative example. Consideration of the defect dynamics, and symmetry-breaking, changes the qualitative behaviour and activates new pathways for carrier capture. Our results reveal the potential importance of metastable defect structures in non-radiative recombination, in particular for semiconductors with anharmonic/ioniccovalent bonding, multinary compositions, low crystal symmetries or highly-mobile defects.

show abstract

Section: Capture Into Metastable Defectsmentioning

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Fig 6. Electron and hole capture cross-section (σ n and σ p ) as functions of temperature T for the Te i (+ ( * ) /0 ( * ) ) charge transition levels in CdTe.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Impact of metastable defect structures on carrier recombination in solar cells

Kavanagh,

Scanlon,

Walsh

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Here supercell size scaling method, Freysoldt-Neugebauer-Van de Walle (FNV) correction and self-consistent charge correction 60 , 61 are used to calculate the formation energy and defect levels as discussed in Supplementary Note 3 . The non-radiative transition is calculated based on NONRAD code 62 , as discussed in Supplementary Note 9 .…”

Section: Methodsmentioning

confidence: 99%

Carbon defect qubit in two-dimensional WS2

et al. 2022

View full text Add to dashboard Cite

Identifying and fabricating defect qubits in two-dimensional semiconductors are of great interest in exploring candidates for quantum information and sensing applications. A milestone has been recently achieved by demonstrating that single defect, a carbon atom substituting sulphur atom in single layer tungsten disulphide, can be engineered on demand at atomic size level precision, which holds a promise for a scalable and addressable unit. It is an immediate quest to reveal its potential as a qubit. To this end, we determine its electronic structure and optical properties from first principles. We identify the fingerprint of the neutral charge state of the defect in the scanning tunnelling spectrum. In the neutral defect, the giant spin-orbit coupling mixes the singlet and triplet excited states with resulting in phosphorescence at the telecom band that can be used to read out the spin state, and coherent driving with microwave excitation is also viable. Our results establish a scalable qubit in a two-dimensional material with spin-photon interface at the telecom wavelength region.

show abstract

Persistent Luminescence in Strontium Aluminate: A Roadmap to a Brighter Future

Heggen

Joos

Feng

et al. 2022

Adv Funct Materials

View full text Add to dashboard Cite

Glow-in-the-dark materials have been around for a long time. While formerly materials had to be mixed with radioactive elements to achieve a sufficiently long and bright afterglow, these have now been replaced by much safer alternatives. Notably strontium aluminate, SrAl 2 O 4 , doped with europium and dysprosium, has been discovered over two decades ago and since then the phosphor has transcended its popular use in watch dials, safety signage, or toys with more niche applications such as stress sensing, photocatalysis, medical imaging, or flicker-free light-emitting diodes. A lot of research efforts are focused on further improving the storage capacity of SrAl 2 O 4 :Eu 2+ ,Dy 3+ , including in nanosized particles, and on finding the underlying physical mechanism to fully explain the afterglow in this material and related compounds. Here an overview of the most important results from the research on SrAl 2 O 4 :Eu 2+ ,Dy 3+ is presented and different models and the underlying physics are discussed to explain the trapping mechanism at play in these materials.

show abstract

Nonrad: Computing nonradiative capture coefficients from first principles

Cited by 68 publications

References 26 publications

Impact of metastable defect structures on carrier recombination in solar cells

Impact of metastable defect structures on carrier recombination in solar cells

Carbon defect qubit in two-dimensional WS2

Persistent Luminescence in Strontium Aluminate: A Roadmap to a Brighter Future

Contact Info

Product

Resources

About