Analysis of the interaction of an electron beam with a solar cell—III. The effect of spacial variations of the number density of recombination centers on SEM measurements
Abstract
By means of an exactly soluble model the short circuit current I_{SC} generated by a scanning electron microscope in a P N junction has been determined in cases where the trap density N_{t} is inhomogeneous. The diffusion length for minority carriers becomes then dependent on the spacial coordinates. It is shown that in this case the dependence of the I_{SC} on characteristic parameters as cell thickness, distance of the beam excitation spot from ohmic contacts etc., becomes very intricate. This fact precludes the determination of the local diffusion length in the usual manner. Although the model is somewhat simplified in order to make it amenable to exact solutions, it is nevertheless realistic enough to lead to the conclusion that SEM measurements of bulk transport parameters in inhomogeneous semiconductor material are impractical since they may lead to serious errors in the interpretation of the data by customary means.
 Publication:

Solid State Electronics
 Pub Date:
 September 1979
 DOI:
 10.1016/00381101(79)901254
 Bibcode:
 1979SSEle..22..773V
 Keywords:

 Electron Beams;
 Electron Diffusion;
 Mathematical Models;
 PN Junctions;
 Solar Cells;
 Electron Density (Concentration);
 Electron Microscopes;
 Electron Recombination;
 Error Analysis;
 Minority Carriers;
 Performance Prediction;
 Short Circuits;
 Electronics and Electrical Engineering