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A5: Nanoscale and low dimensional effects

Thermo power Enhancement in PbTe nanocubes

B Khasimsaheb1,S Neeleshwar1*,B Shivaiah2,Ajay Dhar2,S Amrithapandiyan3 & B K Panigrahi3
1* USBAS, GGS Indraprastha University,New Delhi,India2  National Physical Laboratory,New Delhi,India3  Materials physics divison,IGCAR,Kalpakkam,Tamilnadu,India

Abstract:

In the present investigation, we report synthesis   of PbTe Nanocubes and sheets by refluxing method. Nanostructures were characterized by X-ray diffraction (XRD), Selective Area Electron Diffraction (SAED), High Resolution Transmission Electron Microscope (HRTEM) and Thermo power.   XRD data clearly indicates that all the nanostructures have the same crystal structures as that of bulk which is Cubic. Line broadening was observed in nanostructures due to quantum size effects. Distribution of size, phase and crystalline nature of nanostructures is further confirmed by HRTEM. The conversion of particles into cubes takes place as the reaction time increases, and growth mechanism discussed.  One dimensional to two dimensional morphology change (sheets) was observed by pH variation and confirmed by HR-TEM. These nanostructures exhibits high thermo power 420 μV (300-400 K), the enhancement of thermo power and results will be discussed. 

Keywords: Lead Telluride, Nanocubes, Nanosheets, refluxing method, pH variation, Reaction time, XRD, SAED, HR-TEM & Thermo Power.