Interference Effects in Nonlinear Vibrational Spectroscopy from Multilayered Material Interfaces Aaron M. Massari Department of Chemistry University of Minnesota International Symposium on Molecular Spectroscopy (ISMS) June 17, 2014 Aaron M. Massari Department of Chemistry University of Minnesota International Symposium on Molecular Spectroscopy (ISMS) June 17, 2014

Aaron M. Massari Department of Chemistry University of Minnesota International Symposium on Molecular Spectroscopy (ISMS) June 17, 2014 Aaron M. Massari Department of Chemistry University of Minnesota International Symposium on Molecular Spectroscopy (ISMS) June 17, 2014 Interference Effects in Nonlinear Vibrational Spectroscopy from Multilayered Material Interfaces

Interfaces Are Important gate sourcedrain organic dielectric n-Si electron donor electron acceptor TCO VSFG visible IR VSFG visible IR Not to scale! ~100 micron spot size The entire thin film (~100 nm) VSFG can help.... or can it?

The Two Interface “Problem” mIR frequency (cm -1 ) SFG wavelength (nm) Intensity (arb)

  3 Usual Approach to Calculating Fields

Transfer Matrices: Two Concepts Knittl, Z. Optics of Thin Films; John Wiley & Sons: London, Abeles, F. Recherches sur la propagation des ondes lectromagn tiques sinusoidales dans les milieux stratifi s. Application aux couches minces., Masson: Paris, 1950.

Generalized Multilayer System

Total System Transfer Coefficients

Partial System Transfer Coefficients

Redefine r & t for Single Layer System

Redefine Reflection and Transmission D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138,

1 2 Redefine Reflection and Transmission D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138,

Redefine Reflection and Transmission D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138,

We have a way to describe all fields of interest in any layer of an ideal multilayer system Redefine Reflection and Transmission D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138,

VSFG Simulations D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138,

VSFG Simulations D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30, D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138, Spectral ellipsometry was performed to determine the complex refractive indices at all relevant frequencies

VSFG Simulations J. Chem. Phys. 2013, 138, ssp sps pss T is frequency dependent -Important for SFG active modes -Important for SFG inactive modes T cares about the thickness of the layers T sometimes favors one interface over another

VSFG Simulations ssp sps pss J. Chem. Phys. 2013, 138, Bluer colors favor interface 1 Redder colors favor interface 2 mIR = 1720 cm -1 mIR = 2900 cm -1

Organic Vapor Deposition (OVD) chamber for wedged substrate deposition SFG Experiments

Si Wafer 80mm Si Wafer SFG Experiments Si Wafer ODTMS

SFG Experiments

bare SiO 2 NO bare SiO 2 TO ODTMS NO ODTMS TO ssp data (top), fit (bottom)

SFG Experiments sps data (top), fit (bottom) bare SiO 2 NO bare SiO 2 TO ODTMS NO ODTMS TO

SFG Experiments

“Modeling multilayer thin film interference effects in interface-specific coherent nonlinear optical spectroscopies” D.B. O’Brien, A.M. Massari, J. Opt. Soc. B 2013, 30 (6), “Simulated vibrational sum frequency generation from a multilayer thin film system with two active interfaces” D.B. O’Brien, A.M. Massari, J. Chem. Phys. 2013, 138 (15), Acknowledgments