Structural and optical study of SnO 2 nanobelts and nanowires (original) (raw)
Related papers
Temperature dependent growth and optical properties of SnO2 nanowires and nanobelts
Bulletin of Materials Science, 2010
SnO 2 nanowires and nanobelts have been grown by the thermal evaporation of Sn powders. The growth of nanowires and nanobelts has been investigated at different temperatures (750-1000°C). The field emission scanning electron microscopic and transmission electron microscopic studies revealed the growth of nanowires and nano-belts at different growth temperatures. The growth mechanisms of the formation of the nanostructures have also been discussed. X-ray diffraction patterns showed that the nanowires and nanobelts are highly crystalline with tetragonal rutile phase. UV-visible absorption spectrum showed the bulk bandgap value (~ 3⋅6 eV) of SnO 2. Photoluminescence spectra demonstrated a Stokes-shifted emission in the wavelength range 558-588 nm. The Raman and Fourier transform infrared spectra revealed the formation of stoichiometric SnO 2 at different growth temperatures.
Growth and photoluminescence properties of vertically aligned SnO2 nanowires
Journal of Crystal Growth, 2009
Vertically aligned SnO 2 nanowires (NWs) were grown for the first time by a vapor-liquid-solid method on c-sapphire with gold as a catalyst under Ar gas flow. Electron backscatter diffraction analysis indicated the NWs are single crystalline having the rutile structure, grow vertically along the [1 0 0] direction, and exhibit a consistent epitaxial relationship where lattice mismatch is estimated to be 0.3% along the SnO 2 [0 1 0] direction. The growth of these NWs is sensitive to many parameters, including growth duration, substrate type, source vapor concentration, and the thickness of the catalyst layer. Photoluminescence measurements at room temperature showed that the vertically aligned NWs exhibit an intense transition at 3.64 eV, a near band-edge transition which is rarely observed in SnO 2 .
Electrical and optical properties of single zigzag SnO2 nanobelts
CrystEngComm, 2013
We report here on investigations of electrical and optical properties of single zigzag SnO 2 nanobelts. Large scale zigzag nanobelts were obtained on a silicon substrate by a Chemical Vapor Deposition (CVD) approach. The average value of carrier concentrations (N d ) and electron mobility (m) were calculated to be 1.39 6 10 18 cm 23 and 70.76 cm 2 V 21 s 21 , respectively. Room temperature PL exhibits a broad emission peak centred at 600 nm. Three Raman active modes at 474.8, 633.8, 775.8 cm 21 were observed. Electron paramagnetic resonance measurements suggest the presence of many singly ionized states.
Multiform structures of SnO 2 nanobelts
Nanotechnology, 2007
Multiform SnO 2 microstructures were synthesized by a facile thermal evaporation of tin grains. The product was characterized with a variety of techniques to obtain the structural and optical information. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed a large percentage of acute angle zigzag nanobelts with perfectly periodic morphology. High resolution transmission electron microscopy (HRTEM) images and selected area electron diffraction (SAED) patterns revealed that the zigzag nanobelts were single crystalline and their zone axis was along the [010] crystal direction. The growth mechanism of zigzag nanobelts was proposed based on TEM characterization and thermodynamic analysis. The zigzag nanobelts were deduced to be formed by changing the growth direction from [101] to [101] or vice versa. The photoluminescence (PL) spectroscopy of the nanobelts showed a broad and strong luminescence emission centred at 550 nm.
Nanotechnology, 2009
Controlled synthesis of one-dimensional materials, such as nanowires and nanobelts, is of vital importance for achieving the desired properties and fabricating functional devices. We report a systematic investigation of the vapor transport growth of one-dimensional SnO 2 nanostructures, aiming to achieve precise morphology control. SnO 2 nanowires are obtained when SnO 2 mixed with graphite is used as the source material; adding TiO 2 into the source reliably leads to the formation of nanobelts. Ti-induced modification of crystal surface energy is proposed to be the origin of the morphology change. In addition, control of the lateral dimensions of both SnO 2 nanowires (from ∼15 to ∼115 nm in diameter) and nanobelts (from ∼30 nm to ∼2 μm in width) is achieved by adjusting the growth conditions. The physical properties of SnO 2 nanowires and nanobelts are further characterized and compared using room temperature photoluminescence, resonant Raman scattering, and field emission measurements.
Materials Science in Semiconductor Processing
Tin dioxide (SnO 2 ) ultralong nanobelts were fabricated on silicon substrate by metal catalyzed Chemical Vapor Deposition (CVD) approach. An optical bandgap of 3.66 eV was calculated by optical absorbance data. Three Raman active modes peaks were observed at 474.4, 633 and 774.4 cm À 1 . Room temperature photoluminescence (PL) exhibited an orange emission at 600 nm. A vapor-liquid-solid (VLS) process based growth mechanism for the formation of SnO 2 nanobelts was proposed and discussed briefly. Electrical transport characteristics of nanobelts were studied in dark and under ultraviolet (UV) laser. The fabricated device exhibited high photo-response properties under UV light, indicating their potential application as photo-switches and UV detectors.
Cathodoluminescence of N-doped SnO2 nanowires and microcrystals
AIMS Materials Science, 2016
We present a cathodoluminescence (CL) study of the point defects in N-doped SnO 2 nanowires and microcrystals synthesized by thermal evaporation at different growth temperatures and N concentrations. SnO 2 :N nanowires were grown at temperatures higher than 1150 °C with N concentrations below of about 3 at.%, while irregular microcrystals were obtained at lower temperatures increasing their N concentration gradually with the growth temperature. EELS and XPS measurements confirmed that N atoms were incorporated into the SnO 2 lattice as substitutional impurities (N O). TEM and EDS measurements revealed that the nanowires grew along the [001] direction by a self-catalyzed growth mechanism. CL measurements showed that the nanowires and microcrystals generated a broad emission composed by three components centered at about 2.05, 2.47 and 2.75 eV. CL spectra obtained at 300 and 100 K showed that the component of 2.05 eV decreased in intensity proportionally to the nitrogen content of samples. We attribute this effect to a decrease of oxygen vacancies in the SnO 2 nanowires and microcrystals, generated by the incorporation of nitrogen in their lattice.
CVD grown doped and Co-doped SnO2 nanowires and its optical and electrical studies
Materials Today: Proceedings, 2020
In this study we report the successful synthesis of doped and co-doped SnO 2 nanowire using facile Chemical Vapor deposition (CVD) technique. In this studies, the role of Pr as a codopant in Ba doped SnO 2 nanowires has been investigated for optical, morphological and RT transport studies. Pr codoping significantly tunes the morphology, band gap and electrical properties of SnO 2 nanowires. GAXRD, FESEM, EDAX, UV-Vis and XPS studies have been carried out to establish the effect of Pr co-doping in SnO 2 nanowires. With Pr co-doping, we notice a decrease in band gap from visible transparent range (3.6 eV) to blue emission region (2.1 eV) whereas its mobilities decrease to 28 cm 2 /V-s from 85 cm 2 /Vs Through this studies, we have been able to establish the well known trade-off situation between optical and electrical parameters in TCO materials such as SnO 2 .
Growth of SnO2 nanowires with uniform branched structures
Solid State Communications, 2004
SnO 2 nanowires have been prepared using the active carbon reaction with the fine SnO 2 powder at low temperature (700 8C). These nanowires show rectangular cross-section, with their widths ranging from 10 to 50 nm. Branched nanowires with definite included angle are also observed in these products. The morphology and microstructure of the single crystalline SnO 2 nanowires and the branched nanowires are characterized by means of scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selective area electron diffraction (SAED) and Raman spectrum. In addition, the possible growth mechanism of the SnO 2 nanowires and branched nanowires is also discussed. q