Organic thin films hold great promise for high-speed optical computing applications, for investigating fundamental optical properties of photonic band structures, and as new quantum well structures. We concentrate on hetero-epitaxy of single crystal organic materials with nonlinear optical properties on silicon and investigation of the effect of the preparation of the Si surface in those NLO properties.
The research interests of the Bonner group include hetero-epitaxy of single crystal organic materials with nonlinear optical properties on silicon and observation of the effect of the preparation of the Si surface on those NLO properties using IR-vibrational spectroscopies to identify vibrational modes of Si surface and the organic molecular absorbate and compare them to layers on Si surface. Once these modes are identified, surface-molecule interaction modes will be determined subtraction of the free molecule and substrate vibrational spectra. The eventual objective is to identify the surface molecule interaction energies to observe intramolecular vibrational relaxation as a method of energy storage in the molecule on the substrate surface and define the relationship between intramolecular vibrations and the disposal of energy at the surface. This is expected to lead to improvements in the layered growth of van Deer Waals crystals onto semiconductor substrates.
The other main research interest of the group is the design and characterization of the molecular and macroscopic second hyperpolarizability based properties, two-photon absorption and nonlinear refractive index, in a range of substituted thiacyanine dyes. This project involves the investigation and development of novel and improved asymmetric and symmetric organic charge transfer chromophores for potential applications in two photon absorption (TPA), reverse saturable absorption (RSA) and related materials and devices.