Scanning electron microscope studies of electroluminescent diodes of GaAs and GaP III. Quantitative line scan observations on GaP

Both the barrier electron voltaic effect (charge collection) current and the cathodoluminescence intensity were recorded as the electron beam was scanned across p–n junctions normal to the surface of GaP diodes. Mid‐points for each type of trace were defined and found to be separated by a distance (the CL–CC shift) which correlated with device efficiency. It was found that the magnitude of this shift depended also on the wavelength of light that was detected. The form of the charge collection traces recorded on scanning across the junctions varied with the electron beam voltage in the range from 10 to 30 kV in a simple manner which is however inexplicable in terms of the theories of the barrier electron voltaic effect which were found to apply in the case of GaAs p–n junctions [3]. Copyright © 1973 WILEY‐VCH Verlag GmbH & Co. KGaA