Studies on Cd1Se0.6Te0.4 Thin Films by Spectroscopic and Diffractometer Characterization
Abstract
Cadmium selenide tellurium is a compound containing cadmium, tellurium and
selenium elements forming a combined solid. Hall measurements suggest that it is an ntype
semiconductor. Related optical studies indicate that is transparent to infra-red
radiation. Structural studies clearly show that it has a wurtzite, sphalerite crystalline forms.
Cadmium is a toxic heavy metal, and selenium is only toxic in large amounts or doses. By
this toxicity, cadmium selenide is a known to be carcinogen to humans; however, this does
not stop investigating it for optoelectronic applications. Current research has narrowed
down to investigating cadmium selenide when in the form of nanoparticles. Cadmium
selenide finds applications has found applications in opto-electronic devices like laser
diodes, biomedical imaging, nano-sensing, high-efficiency solar cells and thin-film
transistors. By chemical bath deposition, Cd1Se0.6Te0.4 thin films were grown onto glass.
Tellurium was gradually introduced as an impurity and its crystalline structure and optical
properties were investigated by XRD and UV-VIS spectroscopy. The main
Cd1Se0.6Te0.4/glass characteristics were correlated with the conditions of growing and postgrowth
treatment and it was found out that films were homogeneous films with
controllable thickness onto the glass substrate and suitable for n-type “sandwich”
heterostructures applications. Comparison of the intensities of equivalent reflexions
provided a test for the internal consistency of the measurements. Equivalent reflexions in
two specimens differed on average by 1.4 % and 0.6% from the mean measured intensity,
attesting to the high internal consistency of measurements from extended-face crystals. By
comparison from data obtained from all samples showed their average deviation from the
mean to be 0.9 %.