Subpicosecond Carrier Relaxation Dynamics and Defect Formation in Wide-Band-Gap Materials

Ultrafast carrier nonradiative relaxation dynamics and concomitant band-gap evolutions in bare GaAs and a core–shell GaAs/AlGaAs semiconductor nanowire array.

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Subnanosecond Relaxation Dynamics of 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonate) and Chlorpromazine. Assessment of Photosensitization of a Wide Band Gap Metal Oxide Semiconductor TiO2

The Journal of Physical Chemistry ◽

10.1021/j100011a034 ◽

1995 ◽

Vol 99 (11) ◽

pp. 3636-3642 ◽

Cited By ~ 8

Author(s):

P. Maruthamuthu ◽

D. K. Sharma ◽

N. Serpone

Keyword(s):

Metal Oxide ◽

Band Gap ◽

Wide Band ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Relaxation Dynamics ◽

Wide Band Gap

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Ab Initio Study of MgTe Self-Interstitial (Mgi and Tei): A Wide Band Gap Semiconductor

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.16.47 ◽

2017 ◽

Vol 16 ◽

pp. 47-51

Author(s):

Emmanuel Igumbor ◽

Ezekiel Omotoso ◽

Walter Ernst Meyer

Keyword(s):

Band Gap ◽

Density Functional ◽

Defect Formation ◽

Local Density ◽

Wide Band ◽

Shallow Donor ◽

Generalized Gradient ◽

Wide Band Gap ◽

Functional Theory ◽

Formation Energies

We present results of defect formation energies and charge state thermodynamic transition levels of Mg and Te interstitials in MgTe wurzite structure. We use the generalized gradient approximation and local density approximation functionals in the framework of density functional theory for all calculations. The formation energies of the Mg and Te interstitials in MgTe for both the tetrahedral and hexagonal configurations were obtained. The Mg and Te interstitials in MgTe depending on the functional, introduced transition state levels that are either donor or acceptor within the band gap of the MgTe. The Te interstitial exhibit charge states controlled metastability, negative-U and DX centre properties. The Mg interstitial acts as deep or shallow donor and there is no evidence of acceptor levels found for the Mg interstitial.

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TEM and cathodoluminescence of precipitates in II-VI semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104509 ◽

1988 ◽

Vol 46 ◽

pp. 488-489

Author(s):

Joanna L. Batstone

Keyword(s):

Crystal Growth ◽

Band Gap ◽

Local Strain ◽

Wide Band ◽

Optoelectronic Device ◽

Wide Band Gap ◽

Bulk Crystal Growth ◽

Transmission Electron ◽

Device Applications ◽

Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

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