The deposition of copper selenide(CuSe)thin films was carried out using liquid phase chemical bath deposition process at the optimized growth parameters as:60℃deposition temperature,90 minutes deposition time,pH equa...The deposition of copper selenide(CuSe)thin films was carried out using liquid phase chemical bath deposition process at the optimized growth parameters as:60℃deposition temperature,90 minutes deposition time,pH equal to 10.5±0.1 and 72±2 r/min speed of mechanical rotation.The as-grown deposits exhibited excellent uniformity and physical adherency with the substrate surface and are smooth and diffusely reflecting with colour changing from yellowish orange to dark chocolate during deposition.The layer is of the order of 300 nm thick.The EDS analysis technique gave film composition to be nearly stoichiometric(Cu=47.89%,Se=52.11%).An X-ray diffraction analysis showed CuSe to be polycrystalline hexagonal with a good match of d-values and intensities of reflections.The crystallite size is in the nanorange(50-60 nm).The as-deposited CuSe exhibited a high coefficient of absorption(α=105cm-1)with a direct optical band gap of 1.81 eV.Compared to other chalcogenides,CuSe films exhibit low resistance;room temperature electrical resistivity being 1.55×103?cm.The electrical conductivity decreased with increase in temperature up to 473 K;showing totally unusual behaviour from that of the semiconducting property.The thermo probe measurements showed n-type conduction of the samples.展开更多
A liquid phase chemical bath deposition(LPCBD)method for deposition of PbS thin films is presented.The growth kinetics and reaction mechanism have been discussed.For the deposition,triethanolamine complex of lead acet...A liquid phase chemical bath deposition(LPCBD)method for deposition of PbS thin films is presented.The growth kinetics and reaction mechanism have been discussed.For the deposition,triethanolamine complex of lead acetate was allowed to react with aqueous thiourea solution.Glass micro-slides were used as the substrates.The deposition of PbS films was carried out under different growth parameters such as temperature,time,and reaction pH.The growth rate,under different conditions,was measured in terms of a terminal layer thickness and the possible reaction kinetics and mechanism is discussed.The optimum values of the parameters to produce good quality films are 60 min,80℃and 10.5±0.1.An EDS analysis showed that the film stoichiometry is dependent on the reaction pH and the films tend to be almost stoichiometric in high alkaline environment(>10.5).The PbS deposits appeared smooth,tightly adherent,uniform and reflecting with blackish-grey colour.The XRD studies showed crystalline cubic type of structure with preferred orientation along(200)plane.The calculated d-values,intensities of reflections and lattice parameter have excellent match with that of the JCPD data.The crystallite size is found to be few tens of nanometer.The surface morphology revealed by SEM showed that the crystallites are randomly oriented and are of different shapes and sizes.Majority of the crystallites appeared smaller and spherical in shape whereas,growth of some elongated irregular crystallites;bit larger in size and differing in shapes,have also been favoured.展开更多
文摘The deposition of copper selenide(CuSe)thin films was carried out using liquid phase chemical bath deposition process at the optimized growth parameters as:60℃deposition temperature,90 minutes deposition time,pH equal to 10.5±0.1 and 72±2 r/min speed of mechanical rotation.The as-grown deposits exhibited excellent uniformity and physical adherency with the substrate surface and are smooth and diffusely reflecting with colour changing from yellowish orange to dark chocolate during deposition.The layer is of the order of 300 nm thick.The EDS analysis technique gave film composition to be nearly stoichiometric(Cu=47.89%,Se=52.11%).An X-ray diffraction analysis showed CuSe to be polycrystalline hexagonal with a good match of d-values and intensities of reflections.The crystallite size is in the nanorange(50-60 nm).The as-deposited CuSe exhibited a high coefficient of absorption(α=105cm-1)with a direct optical band gap of 1.81 eV.Compared to other chalcogenides,CuSe films exhibit low resistance;room temperature electrical resistivity being 1.55×103?cm.The electrical conductivity decreased with increase in temperature up to 473 K;showing totally unusual behaviour from that of the semiconducting property.The thermo probe measurements showed n-type conduction of the samples.
文摘A liquid phase chemical bath deposition(LPCBD)method for deposition of PbS thin films is presented.The growth kinetics and reaction mechanism have been discussed.For the deposition,triethanolamine complex of lead acetate was allowed to react with aqueous thiourea solution.Glass micro-slides were used as the substrates.The deposition of PbS films was carried out under different growth parameters such as temperature,time,and reaction pH.The growth rate,under different conditions,was measured in terms of a terminal layer thickness and the possible reaction kinetics and mechanism is discussed.The optimum values of the parameters to produce good quality films are 60 min,80℃and 10.5±0.1.An EDS analysis showed that the film stoichiometry is dependent on the reaction pH and the films tend to be almost stoichiometric in high alkaline environment(>10.5).The PbS deposits appeared smooth,tightly adherent,uniform and reflecting with blackish-grey colour.The XRD studies showed crystalline cubic type of structure with preferred orientation along(200)plane.The calculated d-values,intensities of reflections and lattice parameter have excellent match with that of the JCPD data.The crystallite size is found to be few tens of nanometer.The surface morphology revealed by SEM showed that the crystallites are randomly oriented and are of different shapes and sizes.Majority of the crystallites appeared smaller and spherical in shape whereas,growth of some elongated irregular crystallites;bit larger in size and differing in shapes,have also been favoured.
