The Influence of Sputtering Power on the Structural, Morphological and Optical Properties of ZnSe Thin Films Deposited by R.F Magnetron Sputtering

Abstract

By creatively using R.F Magnetic sputtering technique , we have successfully prepared ZnSe polycrystalline thin films on glass substrates..The effect of different sputtering powers on the structural, morphological and optical properties of the as-deposited films were studied. The films were characterized by using X-ray diffraction, UV-VIS spectrometer ,scanning electrical microscope ,etc. The results indicate that :Under the pressure of o.8pa,with the diverse sputtering power varying from 60w to 100w,the intensities of XRD peaks of ZnSe thin films varied apparently ,while the morphological properties were almost the same. It should be noted here that the crystallinity of the ZnSe film, which was deposited with the power of 90W, showed a face-centered cubic phase. Besides, it showed relatively better performance: with strong [111] orientation ,smooth surface without obvious defects, comparatively large band gap and high transmission rate.

Effects of polycrystalline GeO2 substrates on the structural, optical and electrical properties of ZnSe thin films

“…These films are of better morphology than the ones we reported here. The estimated direct allowed energy band gap of the films grown onto glass substrates by the magnetron sputtering technique being 2.48 eV is larger than [37] those we achieved by the thermal evaporation technique. On the other hand, cubic ZnSe thin films of thickness of 100 nm coated onto indium tin oxide (ITO) substrates by the thermal evaporation technique exhibited larger lattice parameters, smaller crystallite sizes and wider energy band gaps [38].…”

“…It is interesting to compare the structural and optical properties of ZnSe thin films grown by the thermal evaporation technique with films grown by the RF magnetron sputtering technique [37]. These films are observed to exhibit cubic structure with lattice parameters of 5.66 Å.…”

Effect of RF Power on the Structural and Optical Properties of Zinc Sulfide Films

“…The XRD results revealed that a low RF power value of 100 W could not initiate crystallization or the crystal lattice orientation at room temperature since the surface mobility of the particles on the substrate and the kinetic energy of the sputtered particles are low at this low value of RF power [26]. As a result, the sputtered particles cannot arrive at low energy lattice positions, leading to the formation of ZnS films with less ordering or an amorphous nature [27]. An increase in the RF power to 120 W gives sufficient energy to the ad-atoms, increasing their mobility to the low energy lattice positions and leading to crystallization of the film.…”

“…An increase in the RF power to 120 W gives sufficient energy to the ad-atoms, increasing their mobility to the low energy lattice positions and leading to crystallization of the film. The increase in the RF power to 150 W again increases the ad-atom mobility and provides enough diffusion activation energy to occupy the most beneficial lattice positions in an ordered manner, leading to atomic rearrangement and good crystallization of the film [27,28]. Increasing the sputtering power beyond 150 W provides excess kinetic energy to the sputtered particles, which increases the collisions and atomic scattering.…”

“…Increasing the sputtering power beyond 150 W provides excess kinetic energy to the sputtered particles, which increases the collisions and atomic scattering. This causes rebounding of the sputtered particles and prohibits growth of the ZnS film with a high degree of preferential orientation, leading to a reduction in the crystalline quality [27,29]. Since ZnS is a highly efficient luminescent material [30], there is no interest in its amorphous films because its crystallinity is beneficial for light emission [31].…”