Investigation of physical properties of screen printed nanosized ZnO films for optoelectronic applications

Abstract

Abstract. Nanosized ZnO particles derived from chemical co-precipitation route were used for casting ZnO films by screen printing method followed by sintering at two different temperatures. The variation in structural, optical and electrical properties of these films with temperature have been investigated by XRD, SEM, FTIR, Raman, UV-VIS, EPR and four probe analytical techniques. XRD patterns of these films exhibit polycrystalline nature with hexagonal wurtzite structure and SEM images reveal the smooth, dense and without any cracks/damage porous surface morphology. Infrared transmission spectra shows peaks pertaining to Zn-O stretching modes and their multiphonon modes. While Raman spectra exhibited strong peaks of E 2 (high) phonon and overtone of surface phonon mode at 429 cm −1 and 1144 cm −1 respectively with weak components of LO and TO branches. The direct band gap energy of these films showed narrowing of band gap from 3.21 eV to 3.12 eV on increasing sintering temperature from 500 • C to 600 • C. DC conductivity measurements confirmed semiconducting behaviour and showed lowering of activation energy. EPR spectra showed single narrow line resonance signal of g-value ∼ 1.9469 due to oxygen vacancies which are produced during synthesis of ZnO nanoparticles by sol-gel process. These studies revealed that on increasing sintering temperature the crystallinity of the film improves with reduction in lattice deformations in these screen printed ZnO films.

Investigation on physical properties of nanosized copper oxide (CuO) doped with cobalt (Co): A material for electronic device application

“…All rights reserved a vacancy-rich inner phase may favour the crystallite reorganization into larger grains. Also in our case, it is observed that the dislocation density and strain are increased with the decrease of grain size of CuO, this is because in nano regime surface to volume ratio increases 35 .…”

A Review of Various Methods of Synthesizing Nanoparticles and Their Applications

“…Synthesis: Materials used include zinc acetate dehydrate and sodium hydroxide.1.00M NaOH was added to 0.5M zinc acetate dehydrate aqueous solutions dropwise with constant stirring for precipitating zinc oxyhydroxide. The precipitated nanoparticles were filtered, dried at 70 o C and sintered at 450 o C to obtain to oxides of nanoparticles [20]. These nanoparticles were characterized by high resolution XRD, SEM, Energy dispersive X-ray Spectroscopy (EDS), FT Raman and UV-VIS analytical techniques to probe their structure, surface morphology and physical characteristics.…”

EPR Spectroscopy of Different Sol Concentration Synthesized Nanocrystalline-ZnO Thin Films

“…spectroscopy is a very powerful sensitive technique used for the characterization of nature of magnetic impurities/defects and spin dynamics in materials that have paramagnetic defects [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] in nanocrystalline zinc oxide. EPR spectra are scanned by varying the magnetic field at constant microwave frequency (i.e., 9.36 GHz in X-band EPR spectrometer).…”