scholarly journals Structural, Optical and Electrical Characterizations of Cr-doped CuO Thin Films

Author(s):  
Silan BATURAY ◽  
ilhan CANDAN ◽  
Cihat OZAYDIN

Abstract The polycrystalline copper oxide (CuO) thin films have been produced using method of spin coating onto the soda lime glass (SLG) as well as substrate of p-type Si (1 0 0) wafers at 500 ºC in furnace. The obtained undoped and Cr doped thin films of CuO have been comprehensively characterized via X-ray diffraction (XRD), ultraviolet–vis (UV–vis) spectroscopy, the current–voltage ( I – V ) and capacitance–voltage ( C – V ) characteristics for providing information on quality of the crystalline nature, change in energy band gap and electrical properties, respectively. Structural analysis results which obtained from XRD data demonstrate that CuO films conjunction with Cr doping indicated that all thin films have monoclinic polycrystalline nature, with two main peaks (002) and (111) with d hkl about 2.52 and 2.32 Å, respectively. The transmittance and energy band gap value of undoped and Cr doped thin films of CuO ranging in varying concentration ratio have been determined in the wavelength region of 300 to 1100 nm. UV–vis spectrum analysis results indicate that both transmittance value and energy band gap of the CuO films is changed with increasing Cr doping ratio in CuO solution at room temperature. The I–V and C–V characteristic of Cr:CuO/p-Si diodes were associated with the CuO/p-Si diodes. It is seen that doping of Cr had a significant change onv the obtained devices’ performance. Thus, the Cr:CuO/p-Si diodes generated by 1% Cr doping using spin coating method had the highest light sensitivity compared with those of the other diodes.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
A. A. Faremi ◽  
S. S. Oluyamo ◽  
O. Olubosede ◽  
I. O. Olusola ◽  
M. A. Adekoya ◽  
...  

Abstract In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO2), and aluminum chloride (AlCl2·7H2O). Junctions-based Al2Se3 thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al2Se3 thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al2Se3 can find useful applications in optoelectronic devices.


2010 ◽  
Vol 404 (1) ◽  
pp. 186-191 ◽  
Author(s):  
J.-K. Chung ◽  
J. W. Kim ◽  
D. Do ◽  
S. S. Kim ◽  
T. K. Song ◽  
...  

2001 ◽  
Vol 24 (1) ◽  
pp. 57-61 ◽  
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro ◽  
S. L. Sapienza

In this paper, the dependence on the partial pressure of oxygen of the shift in the energy band-gap of CdO thin films for the visible region is investigated from the theoretical point of view on an experimental basis. In our analysis, the role played by the dependence of the carrier density upon the above pressure is emphasized.


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3313 ◽  
Author(s):  
Neli Mintcheva ◽  
Gospodinka Gicheva ◽  
Marinela Panayotova ◽  
Wilfried Wunderlich ◽  
Aleksandr A. Kuchmizhak ◽  
...  

In this paper, we report a new, simple method for the synthesis of CdS and ZnS nanoparticles (NPs) prepared in a basic aqueous medium using metal xanthate as the sulfur source. The structure, morphology, size distribution, optical band gap, and photocatalytic properties of the newly obtained nanomaterials were investigated by UV-Vis spectroscopy, X-ray diffraction, and transmission electron microscopy. The results show that both CdS and ZnS crystallized in cubic phase and formed NPs with average sizes of 7.0 and 4.2 nm for CdS and ZnS, respectively. A blue shift of UV-Vis absorbance band and higher energy band gap values were observed for both materials in comparison with their bulk counterparts, which is in accordance with the quantum confinement effect. The as-prepared nanomaterials were tested in visible-light driven photocatalytic decomposition of methylene blue (MB). After irradiation for 180 min, the degradation rate of MB with a concentration of 8 × 10−6 mol/L mixed with a photocatalyst (CdS or ZnS, both 10 mg in 100 mL solution of MB) was found to be 72% and 61%, respectively. The CdS NPs showed better photocatalytic activity than ZnS, which could be explained by their lower energy band gap and thus the ability to absorb light more efficiently when activated by visible-light irradiation.


2016 ◽  
Vol 28 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Javed Iqbal ◽  
Asim Jilani ◽  
P.M. Ziaul Hassan ◽  
Saqib Rafique ◽  
Rashida Jafer ◽  
...  

2003 ◽  
Vol 764 ◽  
Author(s):  
Sang Yeol Lee ◽  
Yuan Li ◽  
Jang-Sik Lee ◽  
J. K. Lee ◽  
M. Nastasi ◽  
...  

AbstractZnCdO thin films were deposited on (001) sapphire substrates by pulsed laser deposition. Modulation of the energy band gap of ZnCdO was induced by changing the processing parameters. The optical energy band gap of ZnCdO thin films, measured by photoluminescence and transmittance, changed from 3.289 eV to 3.311 eV due to the variation of annealing temperatures. The change of the optical properties was attributed to the change of the stoichiometry of ZnxCd1-xO as illustrated by Rutherford backscattering spectroscopy.


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