Cd Doped ZnO Films Research Articles

CdS sensitized cadmium doped ZnO solar cell: Fabrication and characterizations

Chemical solution deposition of the porous Cd doped ZnO films has been carried out on Indium Tin Oxide (ITO) coated glass substrate. Photosensitization of Cd doped ZnO photo electrode with nanocrystalline CdS is carried out using successive ionic layer adsorption reaction (SILAR) technique. The cadmium nitrate and sodium sulfide anhydrous were used as precursors for Cd2+ and S2−, respectively. The bare ZnO, Cd doped ZnO and CdS sensitized ZnO & Cd:ZnO films were characterized by using scanning electron microscopy, X-ray diffractometry and UV–Vis spectroscopy. The effect of Cd doping and sensitization of CdS on the performance of solar cell was studied by using current-voltage measurement. The enhancement in power conversion efficiency is observed for CdS/Cd:ZnO (0.43%) with that of CdS/ZnO (0.06%) photoanode.

Swift Xe26+Ion Irradiation Effect on Luminescent Properties of Undoped and Cd-Doped ZnO Films

of Undoped and Cd-Doped ZnO Films D.V. Myroniuk, G.V. Lashkarev, I.I. Shtepliuk, V.A. Skuratov, A. Reszka and B.J. Kowalski Frantsevich Institute for Problems of Material Science, NAS of Ukraine, 3 Krzhizhanovsky str., 03680 Kyiv, Ukraine Joint Institute for Nuclear Research, Joliot-Curie 6, 141980, Dubna, Moscow region, Russia Institute of Physics, PAS, al. Lotnikow 32/46, 02-668 Warszawa, Poland Here we report the e ect of the irradiation by 167 MeV Xe ions (in the uence range up to 3×10 ions/cm) on the undoped and Cd-doped (0.4, 0.5 at.%) ZnO lms deposited by radiofrequency magnetron sputtering. As-grown and irradiated samples were investigated by cathodoluminescence spectroscopy. It was found that the radiation causes a decrease in intensity of luminescent peaks and a redistribution of the radiative recombination channels. We revealed that the cadmium incorporation into ZnO lattice enhances the radiation resistance of ZnO lm.

Structural, morphological and optical properties of Cd doped ZnO film grown on a- and r-plane sapphire substrate by MOCVD

Abstract Cd doped ZnO films have been grown on (1 1 −2 0) (a-plane) and (0 1 −1 2) (r-plane) sapphire substrate by metal organic chemical vapor deposition. A maximum cadmium incorporation of 8.5% and 11.2% has been, respectively, determined for films deposited on a- and r-plane sapphire. The optical transmission spectra and energy band-gap equation established by Makino et al. were used to estimate the cadmium mole fraction in layer. Structural, morphological and optical properties of these films were examined using high resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM) and room and low temperature photoluminescence (Pl) as Cd incorporation and employed substrate. X-ray diffraction study revealed that all films had wurtzite phase but solid solution grown on a-plane sapphire are polycrystalline with a preferred orientation along the [0 0 0 1] direction and a-plane (1 1 −2 0) film are epitaxially grown on r-plane sapphire. AFM image show significant differences between morphologies depending on orientation sapphire substrate but no significant differences on surface roughness have been found. The near band-edge photoluminescence emission shifts gradually to lower energies as Cd is incorporated and reaches 2.916 eV for the highest Cd content (11.2%) at low temperature (20 K).

Photoluminescence Properties of Cd Doped ZnO Films Obtained by PLD

Ternary polycrystalline Zn1xCdxO semiconductor films with cadmium content (x) ranging from 0 to 0.23 were obtained on quartz substrate by pulse laser deposited (PLD) technique. X-ray diffraction measurement revealed that all the films were single phase of wurtzite structure grown on c-axis orientation with its c-axis lattice constant increasing as the Cd content x increasing. Atomic force microscopy observation revealed that the grain size of Zn1xCdxO films decreases continuously as the Cd content x increases. Photoluminescence measurements showed that the band gap decreases from 3.27 to 2.78 eV with increasing the Cd content x. Increasing the Cd content x also leads to the broadening of the emission peak. The shift of PL emission to visible light as well as the decrease of resistivity makes the Zn1xCdxO films potential candidate for optoelectronic device.

The Effects of Transverse Magnetic Field on Pulsed Laser Deposition of Cd-doped ZnO Films

The Effects of Transverse Magnetic Field on Pulsed Laser Deposition of Cd-doped ZnO Films

Enhancement of the Ultraviolet Luminescence Intensity from Cd-Doped ZnO Films Caused by Exciton Binding

ZnO films doped with the cadmium (0.4–0.6%) were grown on crystalline sapphire c-Al2O3 substrates applying radiofrequency magnetron sputtering at the temperature of 400 ◦C in Ar–O2 atmosphere. The as-grown films were investigated in detail using X-ray diffraction, X-ray photoelectron spectroscopy, and cathodoluminescence spectra. The X-ray diffraction analysis revealed that the films possess a hexagonal wurtzite-type structure with the dominant crystallite orientation along the c axis. It was found that the small concentration of the cadmium significantly enhances the ultraviolet emission associated with excitonic transitions. We suggest that this enhancement effect mainly results from appearance of the cadmium isoelectronic traps, which may bind an exciton, thereby increasing the probability of radiation recombination. The effect of Cd isoelectronic impurity on structural and luminescent properties of ZnO films is discussed.

Introduction of metal dopants and/or Ag nanoparticles into direct-patternable ZnO thin films formed by photochemical solution deposition

The introduction of metal dopants and nanoparticles into ZnO films influences film conductivity and transparency but the effects of dopants and nanoparticles are not always predictable. The incorporation of Ag nanoparticles into a ZnO film enhanced film conductivity. Less than 1% donor-doping into the ZnO film induced a decrease in film resistance when using both interstitial and substitutional metal-dopants. When a metal-dopant and Ag nanoparticles were introduced into ZnO film simultaneously, the Ag nanoparticles acted as an electron scattering center in the case of Ag or Cd doped ZnO films (interstitially doped). A decrease in the sheet resistance was observed in the case of In or Sn doped ZnO films (substitutionally doped). The transmittance tended to decrease with the incorporation of Ag nanoparticles. This was caused by light absorption from the surface plasmon resonance of the Ag nanoparticles in the film.