Steady-state junction current distribution in p-n GaN diodes measured using low-energy electron microscopy (LEEM)

We report on the measurement of the lateral distribution of the junction current of an electrical biased p-n GaN diode by electron emission microscopy using a low-energy electron microscope. The vacuum level at the surface of the diode was lowered by deposition of cesium to achieve negative electron affinity, allowing overflow electrons at the surface of the biased diodes to be emitted and their spatial distribution imaged. The results were compared to the literature, and a good match with analytical solutions by Joyce and Wemple [J. Appl. Phys. 41, 3818 (1970)] was obtained.

Automated summary

In this study, the lateral distribution of the junction current in an electrical biased p-n GaN diode was measured using electron emission microscopy with a low-energy electron microscope. The vacuum level on the diode surface was reduced by cesium deposition to achieve negative electron affinity, allowing emitted overflow electrons on the biased diode surface to be imaged for their spatial distribution. The obtained results were compared with Joyce and Wemple's analytical solutions [J. Appl. Phys. 41, 3818 (1970)] and showed a good match.