RESUMO
Two-dimensional (2D) van der Waals materials in-plane anisotropy, caused by a low-symmetric lattice structure, has considerably increased their applications, particularly in thermoelectric. MoS2and MoS2/reduced graphene oxide (rGO) thin films were grown on SiO2/Si substrate by atmospheric chemical vapor deposition technique to study the thermoelectric performance. Few layered MoS2was confirmed by the vibrational analysis and the composition elements are confirmed by the x-ray photoelectron spectroscopy technique. The continuous grains lead to reduced phonon life time in A1gand low activation energy assists to enhance the electrical property. The MoS2/rGO has achieved the highestσof 22 622 S m-1at 315 K due to an electron-rich cloud around the electrons in S atoms near the adjacent layer of rGO.
RESUMO
Specifically engineered three-dimensional (3D) and 1D morphologies are expected to play significant roles in the development of next-generation dye-sensitized solar cells. In this study, using a hydrothermal approach without a surfactant or template, we attempted to synthesize a 3D hierarchical rutile titanium dioxide (TiO2 ) architecture by varying the growth temperature and time. X-ray diffraction patterns of the synthesized TiO2 correlated well with rutile TiO2 . Scanning electron microscopy images exhibited different nanostructures, such as nanorods, aggregated nanorods, and 3D TiO2 microflowers comprised of nanorods at 100°C, 130°C, and 160°C, respectively, after growth for 6 h. A significantly improved efficiency was observed for the TiO2 microflowers. The TiO2 microflowers exhibited an efficiency of 1.16%, short-circuit current density of 12.8 mA cm-2 , open-circuit voltage of 0.692 V, and fill factor of 0.67.
