Effect of reaction time on the synthesis of cadmium selenide nanoparticles and the efficiency of solar cell

Cadmium selenide nanoparticles were synthesized by solvothermal method using cadmium acetate,cd(ch3coo)2 and selenous acid (h2seo3) at 60°c,and at different reaction times of 4,8,12 and 16 hours. the synthesized nanoparticles were characterized by xrd,uv,pl,raman,sem and edx spectral analysis. x-ray diffraction analysis confirmed a hexagonal,wurtzite structure and grain sizes were found to be of 15.8,10.5,6.7 and 111.7nm at 4,8,12 and 16 hours respectively. the absorption and photoluminescence spectra of the cdse nanoparticle showed a red shift as the particle size was reduced. the band gap energy was computed from the absorption data and was found to be 1.62,1.76,and 1.8 ev for 4,8 and 12 hours reaction time respectively. the dielectric constant,dielectric loss,and conductivity of cdse nanoparticles were studied over a range of frequency (50 hz - 5 mhz) and temperature (40°c-140 °c). both dielectric constant and dielectric loss decreased with the increase in frequency and temperature. a solar cell was fabricated using tio2 as a photo anode,cdse as a counter electrode,alizarine dye as sensitizer and i-/i3-as electrolyte,and the maximum conversion efficiency of the solar cell was found to be 3.28 %.