| 고객문의 |

Optical Property - Photoconductivity  

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Topography (left image) and photocurrent (right images) with laser source on (top right image) and laser source off (bottom right image) show the effect of light in current generation; note the increased amount of photo-induced current in the upper image.

 

XE-Productivity in Action

Jeongjin Lee, Inhee Choi, Surin Hong, SuSeung Lee, Young In Yang, Younghun Kim, Jongheop Yi; Construction of pcAFM module to measure photoconductance with a nanoscale spatial resolution;  Ultramicroscopy 108 (2008) 1090– 1093 
Equipment: Park Systems XE-150

Abstract: A photoconductive atomic force microscopy (pcAFM) module was designed and the performance was tested. This module consisted of three units: the conductive mirror-plate, the steering mirror and the laser source. The module with a laser irradiation unit was equipped to a conventional conducting probe atomic force microscopy (CP-AFM) instrument to measure photoconductance in a nanoscale resolution.

As a proof-of-concept experiment, the photo-conductance of aggregated fullerene on indium tin oxide (ITO) substrate was measured with this module. The electrical signals (currents) of aggregated fullerene under the conditions of laser on/off at about -10V sample bias voltage were -100 to -160 nA and 0 to -20 nA, respectively. Results indicated that the pcAFM with this module allowed one to observe photoinduced changes of electrical properties in nanodevices with nanoscale spatial resolution.

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Fig 3. (a)3-D topography of the contact point for the I/V curve measurement and (b) the measured I/V curve. The resistance was decreased by a factor of 5~100. The arrow in (a) indicateds the point at the slope of the sub-circle line, ca, 10 nm height from the boom. At this point, the electrical signals (currents) of aggregated fullerene under the conditions of laser on/off at about -10V sample bias voltage were -100 to -160nA and 0 to -20nA, respectively.

 

Materials Science