Characterization of the MgO/GaSe0.5S0.5 Heterojunction Designed for Visible Light Communications
Date
2015-04-21
Authors
Qasrawi, Atef F.
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Abstract
In this study an optoelectronic design is reported and characterized. The
device is made of p-type MgO solved in sodium silicate binder and n-type
GaSe0.5S0.5 heterojunction. It is described by means of X-ray diffraction, optical
absorption and reflection in the incident light wavelength range of 190-1100 nm
and by means of dark and 406 nm laser excited current (I)-voltage (V)
characteristics. The optical reflectance was also measured as a function of angle of
incidence of light in the range of 35-80o. The structural analysis revealed no
change in the existing phases of the device composers. In addition, it was
observed that for pure sodium silicate and for a 67% content of MgO solved in
sodium silicate binder (33%), the heterojunction exhibits a valence band splitting
of 0.45 and 0.70 eV, respectively. The painting of MgO improved the light
absorbability significantly. On the other hand, the angle-dependent reflectance
measurements on the crystal displayed a Brewster condition at 70o. The MgO/
GaSe0.5S0.5 heterojunction exhibited no Brewster condition when irradiated from
the MgO side. Moreover, for the crystal and the MgO/GaSe0.5S0.5 heterojunction,
the dielectric spectral analysis revealed a pronounced increase in the quality
factor of the device. The I V characteristics of the device revealed typical
optoelectronic properties with high photoresponse that could amplify the dark
current 24 times when irradiated with 5 mW power laser light. The structural,
optical, dielectric and electrical features of the MgO/GaSe0.5S0.5 heterojunction
nominate it for use in visible light communication technology
Description
Keywords
Optical materials , Heterojunction , Impedance spectroscopy , Microwave