In this work, the adopted method of the CdSe doped with Cu
(CdSe: Cu) photodetector is presented. This detector is prepared by vacuum
evaporation of CdSe films on a glass substrate followed by vacuum annealing
under an argon atmosphere for doping with copper. The detector is found, for
the first time, to cover a wide range of the infrared besides the visible
region of the electromagnetic spectrum. This finding of the wavelength tuning
is due to the localized energy states of copper atoms inside the band gap of
the CdSe. These characteristics stem from the unique band structure of CdSe: Cu.
This tuning is compared with recent work in the corresponding colloidal
CdSe-ZnS core shell quantum dots and with the quantum well (QWIR) and quantum
dots infrared detectors (QDIR). The major significance of this developed
detector is in its synthesis simplicity and its fabrication processes costs in
comparison with that of the (QWIR) and (QDIR) detectors. The structural
analysis results demonstrated that the vacuum annealing in competition with the
doping concentration improves significantly the film structure. A better
crystalline structure is reported at 5 wt% of Cu concentration and at annealing
temperature of 350ºC. Besides the measured specific detectivity at room
temperature is D*=2.31×108 cm Hz1/2W-1. This value approaches the detectivity
of the state of art mercury cadmium telluride (MCT). This result paves the way
for further investigations and improvements.
Author(s) Details Professor Hassan H. Mohammed
Department of Computer Engineering Technology, Iraq University College, Alestiqlal Street, Basrah, Iraq.
Professor Salwan K. J. Al-Ani
Department of Physics, College of Science, Al-Mustansiriya University, Baghdad, Iraq.
View Book: - http://bp.bookpi.org/index.php/bpi/catalog/book/171
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