Chemical Synthesis and Properties of Novel Bi2Se3 Nanostructures and Microplatelets

Abstract

Bi 2 Se 3 nanostructures, microsised fibre bundles, and platelets have been synthesised through a simple chemical spray pyrolysis route on glass substrates. Low substrate temperatures (T sub ) favoured growth of nanostructures while elevated T sub was accompanied by increased grain growth and formation of microsised platelets. The nanostructures were identified as nanorods, nanofibers, nanotubes, nanoflowers, and nanoneedles of various aspect ratios. There was an observed red shift of the optical band gap (E opt g ) with increased T sub from 2.40 eV at 95• C to 1.25 eV at 360 • C. Thermo probe measurements confirmed ntype conductivity with dark resistivities which followed a near exponential decline with elevated T sub . The observed changes in optoelectronic properties existing in the different T sub regimes were explained on the basis of microstructural and textural changes in the pristine clusters.

Preparation and Investigation of structure, optical , nonlinear optical and thermoelectric properties of Bi2Se3 thin film

“…Bi 2 Se3 Thin films have been prepared using various techniques such electro deposition [12] and Successive Ionic Layer Absorption and Reaction (SILAR) 13] methods] .The structure of Bi 2 Se 3 thin films were studied [14][15][16][17][18][19][20], It was found that, these films had polycrystalline structure with rhombohedral structure of Bi 2 Se 3 [17][18], space group (R¯3m) (166) [20]. Optical properties of Bi2Se3 thin films were studied [21][22][23][24][25][26][27], It was found that, the energy gap was 1.51 [21], with range 1.4 -2.25 eV [22], 1.10 eV and decrease with annealing [23],1.25 eV decrease with substrate temperature [24], 1.22 eV decreased wit temperature [25]. the transmitted values increased with annealing [26], The Bi2Se3 thin films had a direct transitions [27].…”