title: Two color, low intensity photocurrent feedback for local photocurrent spectroscopy.
abstract: In this work, we introduce a two color, low intensity photocurrent feedback method for photocurrent spectroscopy utilizing an atomic force microscope (AFM). In most applications, measurements with weak optical excitations are not feasible with an AFM because the powerful AFM feedback laser severely disturbs the measurements. Therefore, we have developed a feedback system based on the pressure dependent Schottky barrier height at the tip-sample interface. The versatility of the new feedback system is demonstrated by recording high resolution photocurrent spectra on GaAsInAs heterostructures.
authors.affiliation: Institut für Festkörperelektronik, TU-Wien, Floragasse 7, A-1040 Vienna, Austria. wolfgang.brezna@tuwien.ac.at
authors.forename: W
authors.initials: W
authors.lastname: Brezna
authors.forename: G
authors.initials: G
authors.lastname: Strasser
authors.forename: J
authors.initials: J
authors.lastname: Smoliner
mesh_terms: D003116:Color; D003124:Colorimetry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D018625:Microscopy, Atomic Force / Q000295:instrumentation* / Q000379:methods; D010777:Photochemistry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods