Polymeric thin film optoelectronic devices

The revolution in information technology industry has changed the scenario of scientific and technological research completely. So far the discrete electronic devices were in use for performing the job of switching, multiplexing, frequency modulation etc, it is now the molecule itself, which is required to do the above mentioned phenomena. The rapidly developing area of all optical computing and communication technologies has led to innovations in low cost, processible, highly nonlinear optical materials. These polymers contain polarizable side change groups, which may be oriented by several techniques. The most important use of such non-linear optical materials is as the second order materials for frequency shifting (harmonic generation and parametric mixing) and electro-optical modulation. Second harmonic generation is a non-linear phenomenon whereby two photons at the fundamental frequency are converted into one photon at the harmonic frequency. Studies of the production of SHG including all even orders of non-linear optical phenomenon on reflection at a surface have been restricted to centrosymmetric materials because for all media with a center of symmetry SHG production within the material bulk is forbidden under the dipole approximation and hence the reflected second harmonic signal is inherently surface specific due to broken symmetry at the surface. Due to the very narrow layer of material at the surface, where the second harmonic photons originate, the efficiency of the surface generation process has been estimated to be low. Thin films of poly (methylmethacrylate) with aminobenzophenone side chains have been observed to exhibit strong electrical and optical non-linearity. The electrical, optical and structural characterization of the thin films of aminobenzophenone suggests that thin films of aminobenzophenone with poly (methylmethacrylate) have strong potential for use as frequency doubler for optoelectronic applications. The preparation and non-linear characterization of aminobenzophenone thin films is reported here.