ABSTRACT
The
deposition of undoped and Y-doped CuSe, CdSe and CoSe with different dopant
concentration (0.01 – 0.04mol%) and varying substrate temperature (140oC
– 200oC) have been successfully carried out using spray pyrolysis
technique. The effect of the yttrium doping and substrate temperature variation
on the optical, electrical and structural properties of all the deposited samples
were reported in this research work. For the undoped and Y-doped CuSe, the
optical studies revealed an energy bandgap ranging from 3.0eV to 2.5eV and
introduction of Y dopant was observed to narrow the energy bandgap of pure
CuSe. The electrical studies result supported the fact that the thin films are
semiconductors. The XRD pattern reveals that the deposited films exhibited a
polycrystalline cubic structure with preferred orientation along (200) and
improved crystallinity with yttrium doping. For variation in substrate
temperature, the optical analysis showed that the samples have energy band gap
value ranging from 1.44 eV to 1.8 eV. Increase in substrate temperature was
found to decrease the conductivity thereby increasing the resistivity and
thickness. The XRD pattern revealed a polycrystalline cubic structure with most
preferred orientation along (111) plane for all the films irrespective of the
substrate temperature. YCuSe deposited at 140oC was seen to exhibit
the best crystallinity. In summary, we conclude that substrate temperature of
140oC is the optimum substrate temperature to grow YCuSe. For the
undoped and Y-doped CdSe, the influence of Y-incorporation and variation (0.01,
0.02, 0.03 and 0.04mol%) were clearly seen. The energy bandgap was observed to decrease from 1.71eV for undoped
CdSe to 1.41eV for Y-doped. Increase in Y-concentration from 0 to
0.04m0l%, led to a decrease in the resistivity of CuSe with decreasing film
thickness and increasing conductivity value. The XRD patterns reveal that all
the deposited films are polycrystalline in nature having hexagonal structure
with the preferred orientation and highest intensity along the (100) plane.
Introduction of yttrium dopant was observed to improve the crystallinity of
CdSe. The general result
shows that YCdSe films are good materials for the production of photovoltaic
cells. For variation in
substrate temperature, YCdSe deposited at 180oC exhibited better
optical property when compared to other films with an energy band gap value of
1.50eV. The electrical studies, shows that increase in substrate temperature of
the thin material decreases the resistivity with increasing thickness and
increasing conductivity which reveals that the films are semiconducting. The
XRD analysis revealed a polycrystalline hexagonal structure with most preferred
orientation along (100) plane for all the films irrespective of the substrate
temperature.Y/CdSe deposited at 160oC gave the best crystallinity.
For the undoped and Y-doped CoSe, the optical analysis gave moderate (> 50%)
transmittance with energy bandgaps ranging from 1.25eV to 1.81eV. Incorporation
of yttrium dopant to the CoSe films was observed to enhance the optical
features and the electrical studies reveals that the films are semiconducting
materials. The XRD result revealed a polycrystalline cubic structure and
introduction of higher concentration of yttrium dopant on the films enhanced
the crystallinity. For variation in substrate temperature, the optical
properties were found to vary with substrate temperature despite the fact that
the variation was not totally linear as the film deposited at substrate
temperature of 160oC deviated from the linearity in all the optical
properties. The energy band gap of the deposited samples ranges from 1.25 eV –
1.75eV. The electrical analysis revealed that the substrate temperature and the
film thickness varies directly with conductivity and inversely with resistivity
which is one of the features of a typical semiconductor. The XRD result shows
that the films are cubic polycrystalline in nature andY/CoSe grown at substrate
temperature of 180oC gave the most excellent crystalline quality and
a preferential orientation along (111) direction. From our findings we observe
that these new materials can be used for photovoltaic purposes.
AKPU, A (2023). Growth And Characterization Of Yttrium Doped Chalcoginide Semiconductors For Solar Energy Purposes Using Spray Pyrolysis Technique.. Mouau.afribary.org: Retrieved Dec 22, 2024, from https://repository.mouau.edu.ng/work/view/growth-and-characterization-of-yttrium-doped-chalcoginide-semiconductors-for-solar-energy-purposes-using-spray-pyrolysis-technique-7-2
AKPU, AKPU. "Growth And Characterization Of Yttrium Doped Chalcoginide Semiconductors For Solar Energy Purposes Using Spray Pyrolysis Technique." Mouau.afribary.org. Mouau.afribary.org, 02 Jun. 2023, https://repository.mouau.edu.ng/work/view/growth-and-characterization-of-yttrium-doped-chalcoginide-semiconductors-for-solar-energy-purposes-using-spray-pyrolysis-technique-7-2. Accessed 22 Dec. 2024.
AKPU, AKPU. "Growth And Characterization Of Yttrium Doped Chalcoginide Semiconductors For Solar Energy Purposes Using Spray Pyrolysis Technique.". Mouau.afribary.org, Mouau.afribary.org, 02 Jun. 2023. Web. 22 Dec. 2024. < https://repository.mouau.edu.ng/work/view/growth-and-characterization-of-yttrium-doped-chalcoginide-semiconductors-for-solar-energy-purposes-using-spray-pyrolysis-technique-7-2 >.
AKPU, AKPU. "Growth And Characterization Of Yttrium Doped Chalcoginide Semiconductors For Solar Energy Purposes Using Spray Pyrolysis Technique." Mouau.afribary.org (2023). Accessed 22 Dec. 2024. https://repository.mouau.edu.ng/work/view/growth-and-characterization-of-yttrium-doped-chalcoginide-semiconductors-for-solar-energy-purposes-using-spray-pyrolysis-technique-7-2