The Role of Nitrogen Vacancy in Optical Transitions in GaN

Authors

Presenter(s)

Malik Malone

Files

Description

Nominally undoped n-type Gallium Nitride (GaN) layers grown by metalorganic chemical vapor deposition (MOCVD) on silicon substrates were studied. Thermal Admittance Spectroscopy (TAS) and Optical Admittance Spectroscopy (OAS) techniques were used to characterize these layers. Using Thermal Admittance Spectroscopy (TAS), a defect level was observed at Ec – 0.051 eV and this defect is correlated with the nitrogen vacancy (Nv) in GaN. The samples were illuminated with a monochromatic light with wavelengths (λ) ranging from 200 nm to 450 nm. The OAS spectrum was measured at different temperatures and with different excitation light intensities. The spectrum shows a maximum photoconductance (G) peak at λ = 365nm (E = 3.40eV). This peak is attributed to transitions from the valence band to the donor level at Ec – 0.051 eV. The analysis of the results shows that the saturation level (Gm) of the photoconductance is a function of both light intensity and temperature. The photoconductance decay, after illumination has been terminated, is adequately described by a stretched exponential function. This photoconductance decay is attributed to the thermal emissions of photo-excited carriers from the donor level to the conduction band.

Publication Date

4-9-2014

Project Designation

Independent Research

Primary Advisor

Andrew Evwaraye

Primary Advisor's Department

Physics

Keywords

Stander Symposium project

Disciplines

Arts and Humanities | Business | Education | Engineering | Life Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics | Social and Behavioral Sciences

Recommended Citation

"The Role of Nitrogen Vacancy in Optical Transitions in GaN" (2014). Stander Symposium Projects. 545.
https://ecommons.udayton.edu/stander_posters/545