In phase

1. Position-Dependent Properties of Novel Electronic Materials: Tunneling, Infrared, and Electromechanical MeasurementsJoseph W. Brill, University of Kentucky Research Foundation, DMR 0801764 We are studying the infrared electro-optic (EO) response of semiconducting organic crystals used in thin film transistors. The graph shows the relative change in reflectance (n ~ 900 cm-1) of a “TIPS-pentacene” crystal on a polymer (PVP) thin film dielectric over a gold gate at two locations, one midway between the gold drain and source electrodes and one adjacent to the drain, when a -50V square wave at frequency F is applied to the gate (Vds = 0). The EO response is due to absorption by the field-induced surface charge on the organic crystal, and its “turn-off” at 1 kHz gives a direct measurement of the mobility of the holes in the TIPS-pentacene, 0.1 cm2/Vs. This may be the first observation of light absorption by a charged monolayer and this technique can be used to measure mobility of field-induced charges when the quantity of the charge is unknown. Center of crystal In phase Adjacent to drain 1/2ptcenter = 1 kHz Quadrature

2. Position-Dependent Properties of Novel Electronic Materials: Tunneling, Infrared, and Electromechanical MeasurementsJoseph W. Brill, University of Kentucky Research Foundation, DMR 0801764 In Summer 2010, two undergraduate educationmajors worked full time in our labs, one (Brandi, left photo) on building drive circuits for scanning tunneling microscopes and the other (Natalie, center in right photo) on preparing and characterizing organic thin film transistors. The goal of this program was to provide the students with experience in how science research is done and with a science experience they can share with their future students. They worked closely with graduate students, who also greatly benefited from explaining their work to these scientifically naïve but excited undergraduates, as well as a high school student and a physics undergraduate student.