Scanning Surface Potential Microscopy of Spores on Planar Surfaces

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Electrical characterization of defect states in local conductivity domains in ZnO:N,As layers

P- and n-type conductivity domains in dual-doped ZnO:As+N layers grown by metal organic vapor phase epitaxy on GaN–sapphire templates were electrically microcharacterized by scanning capacitance microscopy (SCM) and scanning surface potential microscopy (SSPM) techniques with respect to their defect states. The p-type domains were found to be dominated by two acceptors with thermal activation energies of about 80 and 270 meV, as observed by transient SCM scans at different temperatures. Optically excited SSPM scans revealed defect-to-band transitions at 400, 459, and 505 nm omnipresent in both domain types as well as a shallower transition at 377 nm exclusively in the p-type regions. According to the similar energy levels, the optical transitions at 377 and 400 nm are assigned to acceptor states, whereby the 80-meV acceptor is probably responsible for the conversion from n- to p-type regions in the domains.

Scanning Surface Potential Microscopy of Light-Induced Electric Potential from Photosystem I and Photosystem I Reconstituted Proteoliposomes

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006