P-type CdS thin films formed by in situ Cu doping in the chemical bath
ABSTRACT The formation of p‐type CdS thin films, doped with Cu, in a chemical bath, is reported for the first time. The Cu doped films showed amorphous nature and exhibited high electrical conductivity as compared to undoped films, which were near stoichiometric with n‐type conductivity and crystalline in nature. Cu doping influenced the photocurrent response, structural, electrical, and optical properties of the films. The optical band gap of the CdS film varied from 2.35 to 2 eV after Cu doping. The potential application of these films as an absorber layer in thin film solar cells is being investigated.
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ABSTRACT: The obstacle to realize the large-scale production of dye-sensitized solar cells (DSSCs) is its long-term stability and reliability problem. One of the main causes of the instability of DSSCs is the use of liquid electrolytes. In addition, exploring nano-sized particles of CdS as an alternative sensitizer for organic dye in dye-sensitized solar cells have attracted great interest due to the high cost and the instability of the organic dye. Our study has found that the CdS-coated TiO2 cell degrades rapidly in the liquid electrolytes even under dark environment. In this work, a solid-state solar cell structure of Glass/FTO/TiO2/CdS:Cu/FTO/glass was successfully made with an efficiency of 0.7%. CdS:Cu served as both the p-type conductor and absorber. No efficiency was obtained for cell structures of glass/FTO/TiO2/CdS/FTO/glass. This indicates the effectiveness of hole conducting behavior of CdS:Cu. This is the first time that this type of solid-state solar cell is reported and improved stability is demonstrated.Journal of Solid State Electrochemistry 03/2011; 16(3). DOI:10.1007/s10008-011-1496-3 · 2.23 Impact Factor
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ABSTRACT: The formation of p‐type CdS thin films in a chemical bath doped with Cu is reported. Cu‐doped films showed an amorphous nature and exhibited high electrical conductivity and quick photoresponse characteristics at high and low levels of Cu doping, respectively. Undoped CdS films were near stoichiometric, crystalline in nature, and exhibited slow photodecay. Cu doping influenced the photoresponse characteristics, structural, electrical, and optical properties of the films. The optical band gap of CdS film changed from 2.35 to 2 eV after Cu doping. These films may be used as a second layer on top of a lower band gap material in thin film solar cell structures and in wide range photo‐IR detector structures. © 1995 American Institute of Physics.Journal of Applied Physics 06/1995; 77(9-77):4548 - 4551. DOI:10.1063/1.359417 · 2.19 Impact Factor
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ABSTRACT: ZnCdS films were formed by in situ chemical doping of CdS with Zn in a chemical bath. The X-ray diffraction (XRD) patterns of CdS films after Zn doping showed a more disordered nature, consisting of reflections from Zn0.049Cd0.951S (JCPDS 40-834) as well as CdS greenockite (hexagonal, JCPDS 41-1049) and hawleyite (cubic, JCPDS 10-0454) phases. A comparison of the optical transmittance spectra for undoped and Zn-doped films showed that the cut-off wavelength was modified after Zn doping, indicating the presence of impurity states in the band gap. Zn-doped films showed an increase in dark conductivity after annealing at about 200°C. These films exhibit promising characteristics for application in solar cell and photodetector structures.Advanced Materials for Optics and Electronics 09/1995; 5(5):269 - 275. DOI:10.1002/amo.860050505