Title :
Local photocurrent and resistivity measurements with micron resolution
Author :
Hiltner, J.F. ; Sites, J.R.
Author_Institution :
Colorado State Univ., Fort Collins, CO, USA
Abstract :
The high resolution laser stepping apparatus developed at Colorado State University has been employed to investigate the response of CdTe-based solar cells to incident laser illumination with very high resolution. The local cell characteristics can be determined by measuring the photocurrent as a function of bias with various intensities and spot sizes. In addition, the high spatial resolution of the instrument makes it possible to examine local variations in resistivity, including regions containing localized defects and single grain boundaries. PSpice modeling of an equivalent circuit has been employed to fit individual apparent quantum efficiency (AQE) versus bias curves. It was determined that, while resistive effects are the dominant mechanism for local variations in photocurrent, high injection effects cannot be ignored when fitting the data
Keywords :
II-VI semiconductors; SPICE; cadmium compounds; crystal defects; electrical conductivity measurement; equivalent circuits; grain boundaries; photoconductivity; solar cells; CdTe; CdTe-based solar cells; Colorado State University; PSpice modeling; apparent quantum efficiency; bias curves; equivalent circuit; high injection effects; high resolution laser stepping apparatus; high spatial resolution; incident laser illumination; localized defects; micron resolution; photocurrent measurements; resistive effects; resistivity measurements; single grain boundaries; Conductivity; Diodes; Doping; Equivalent circuits; Grain boundaries; Lighting; Photoconductivity; Photovoltaic cells; Spatial resolution; Voltage;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.915894
