Surface-enhanced infrared external reflection spectroscopy at low reflective surfaces and its application to surface analysis of semiconductors, glasses, and polymers

Abstract

A surface-enhanced Infrared reflection spectroscopy has been developed for the characterization of thin organic films on low reflective substrates. The substrates we studied were BaF2, Ge, microscope slide glass, and poly(acrylonltrlle-butadlenestyrene) resin. The sensitivity of the reflection Infrared spectroscopy at these surfaces Is remarkably Improved by evaporating very thin silver films on the sample surfaces. The same results were obtained also by casting thin organic films on metal-coated substrates. The Improvement of the spectral sensitivity Is due to the enhancement of the Incident Infrared field at the metal surfaces. We show that this technique Is promising as a surface analytical tool for semiconductors and Insulators. The optimum optical condHIons to obtain the spectra are discussed experimentally and theoretically.

A New Surface for Surface-Enhanced Infrared Spectroscopy: Tin Island Films

“…Osawa and Ikeda 8 also report an electromagnetic EF of 20-30 for transmission IR spectra on silver islands and an enhancement factor of 20-50 for the case of reflectionabsorption SEIR. 9 In our own SEIR work on silver island films the optimum EF was found to be ca. 30.…”

Surface enhanced imaging and IR spectroscopy of the biological cells on the nanostructured gold film

“…When incident light promotes excitation of molecules or cells adsorbed on a gold substrate, the probability of optical process near metal surface is increased due to enhancement of local electric field and density of photon states. Naturally, this effect depends on morphology of gold surface, sizes of roughness and film thickness [17][18][19][20].…”

“…This fluorescence can be enhanced by local electromagnetic field of plasmons excited at the gold rough surface [27,28]. Thus, gold substrate is a source of both proper fluorescence and enhanced local electromagnetic field that can effect on optical process near metal surface [19,20]. Fig.…”

Surface-Enhanced Infrared Absorption

“…Enhanced spectra can be observed in the transmission [9,10], attenuatedtotal-reflection (ATR) [5,6,7], external-reflection [11], and diffuse-reflection modes [12]. In ATR and external-reflection measurements, the observed band intensities depend on the polarization and angle of incidence of the infrared radiation [11,13,14]. 2.…”

“…Since fine metal particles have high catalytic activity in many reactions, SEIRAS is very promising for catalysis research [16,17,19,49,50,51]. Surfaces of nonmetallic materials, such as polymers, semiconductors, glass, human skin, and agricultural products, can also be analyzed by this technique [11,52,53]. Among several applications, great success has been achieved in its application to dynamic studies of electrochemical interfaces [8,25,54,55,56,57,58].…”