Absorption spectra of semiconducting nanoparticles with conducting polymer

The absorption spectra are produced when ions or molecules absorb electromagnetic radiation in ultra violet or visible region when as organic molecules absorb energies available in UV region. The absorption spectra of molecules are very useful in understanding the oxidation states, analysing and characterizing the conducting polymers. We have studied UV-Visible spectrum of molecules which provides information about structure and stability of materials This work tends to study the conducting polymers in which Poly-aniline (PANI) is a most tenable member which can be used in sensors and electro chromic devices. We have also considered II-VI semiconductor nanomaterials as they possess large variation of band gap as function of particle size which is a consequence of quantum confinement and vast applications in solar cells, fluorescent materials and photonic research. Various kinds of electronic excitations may occur in organic molecules by absorbing the energies available in UV-Vis region. UV-Vis spectrum of PANI, CdS and ZnSnanoparticles and their composites with different weight % have been recorded along with the energy band gap particle size of semiconducting nanoparticles. It is generally noticed that nano particles made of semiconducting elements change their optical properties comparative to their bulk materials and a significant shift in optical absorption spectra towards blue region is noticed. The absorption band observed in the UV-Vis spectra of samples is recorded with corresponding optical band energies. The energy band gap and particle size of CdS and ZnS along with their nano composites are calculated from UV- Vis spectra and recorded simultaneously. On the basis of recorded data it is observed that, there are two absorption maxima, one in the UV region and other in the visible region for PANI as well as their semiconducting nanocomposites. Thus using measured data, fluorescence spectra of PANI, PANI-CdS and PANIZnS have been drawn between wavelength and intensity. The band gap of the synthesized CdS and ZnS confirms the formation of nanosized inorganic semiconductors. The calculated values of particle size and band gap energy of materials reveal the variation of opto-electronic properties. It is also observed that PANI and its CdS and ZnS composites are similar in nature and increase in absorption intensity indicating the interaction of CdS and ZnS with conducting polymer. This work will be fruitful in studying the optoelectronic devices.