Urbach tail
E484703
The Urbach tail is an exponential absorption edge observed in the optical spectra of disordered or amorphous semiconductors, reflecting localized states and disorder in the material’s band structure.
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
absorption edge
ⓘ
optical phenomenon ⓘ solid-state physics concept ⓘ |
| appearsBelow | fundamental absorption edge ⓘ |
| associatedWith |
sub-bandgap absorption
ⓘ
tail states in band gap ⓘ |
| characterizedBy |
Urbach energy
ⓘ
slope of exponential absorption tail ⓘ |
| dependsOn |
electron-phonon coupling
ⓘ
structural disorder ⓘ temperature ⓘ |
| describes | exponential absorption edge ⓘ |
| hasAlternativeName |
Urbach energy tail
ⓘ
Urbach rule NERFINISHED ⓘ |
| hasDiscoveryBy | Franz Urbach NERFINISHED ⓘ |
| hasDiscoveryYear | 1953 ⓘ |
| hasDomain |
condensed matter physics
ⓘ
materials science ⓘ semiconductor physics ⓘ |
| hasMathematicalForm | exponential dependence of absorption coefficient on photon energy ⓘ |
| indicates | degree of disorder in a semiconductor ⓘ |
| influences |
device efficiency in optoelectronics
ⓘ
optical losses in solar cells ⓘ sub-bandgap absorption in LEDs ⓘ |
| measuredBy |
optical absorption spectroscopy
ⓘ
photoluminescence spectroscopy analysis ⓘ photothermal deflection spectroscopy ⓘ |
| modeledBy | exponential law for absorption coefficient ⓘ |
| occursIn |
amorphous semiconductors
ⓘ
crystalline semiconductors with disorder ⓘ disordered semiconductors ⓘ optical absorption spectra ⓘ semiconductors ⓘ |
| relatedTo |
band edge absorption
ⓘ
disorder in solids ⓘ electronic band structure ⓘ localized electronic states ⓘ phonon interactions ⓘ temperature-dependent absorption ⓘ |
| relevantTo |
amorphous silicon
ⓘ
chalcogenide glasses ⓘ organic semiconductors ⓘ perovskite semiconductors ⓘ |
| usedIn |
analysis of amorphous materials
ⓘ
characterization of optical quality of semiconductors ⓘ evaluation of defect density in semiconductors ⓘ optoelectronic device optimization ⓘ photovoltaic material characterization ⓘ |
Referenced by (1)
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