Shoji Yamaguchi

Resistivity, carrier concentration, and carrier mobility of electrochemically deposited CdTe films

The electrical type, resistivity, and donor or acceptor concentration of CdTe films deposited electrochemically at various potentials were measured. The carrier mobilities of the films were determined from these results. The deposition potential dependence of the mobility was small and the deposition potential dependence of the resistivity was mainly controlled by the deposition potential dependence of the donor or acceptor concentration. The carrier mobilities were very small compared with those in single crystals due to the scattering of the carriers at grain boundaries.

Resistivity Correction Factor for the Four-Probe Method: Experiment I

Experimental verification of the theoretically derived resistivity correction factor F is presented. Factor F can be applied to a system consisting of a disk sample and a four-probe array. Measurements are made on isotropic graphite disks and crystalline ITO films. Factor F can correct the apparent variations of the data and lead to reasonable resistivities and sheet resistances. Here factor F is compared to other correction factors; i.e. FASTM and FJIS.

STM Tip Induced Phase Transition of Copper Tetracyanoquinodimethane (CuTCNQ)

Abstract We have demonstrated a field-induced, charge-transfer reaction driven by the electric field at the STM tip when the field generated by the STM exceeds the switching threshold of CuTCNQ charge transfer complex. We discuss the mechanism of this nanoscopic phenomenon in comparison with macroscopic observations.

STM Imaging and Surface Modifications on Thin Films and Single Crystals of the Conducting Metal-Organic Complex: Cu(2,5-DM-DCNQI)2

Abstract Single crystals and thin films of a highly conducting transition metal complex, copper bis(2,5-dimethyl-N,N′-dicyanoquinonediimine)have been imaged and modified using the scanning tunneling microscopy (STM). Applications for the nanometer lithography were demonstrated.