We report new type of micro-EL instrument and its applications for light emitting devices. Our new micro-EL, so-called confocal scanning electroluminescence sprctro-microscope (CSESM) has not only fast image acquisition time but also high image resolution. The newly developed CSESM is combined with confocal laser scanning photoluminescence micsoscope, i.e. micro-PL. Therefore, micro-EL distribution can be directly matched with micro-PL and mechanical chip structure of LED. It is fruitful for providing a fast and non-destructive method to analyze the homogeneity of LEDs in its completely proceeded form. Using this apparatus, we study local intensity and wavelength distribution of electroluminescence for InGaN/GaN blue LED chip. Our results represent that local fluctuations of electroluminescence intensity and wavelength position are closely connected with the fluctuation of local current density, i.e. current spreading features on LED chips.

Date Published: 8 February 2007
PDF: 6 pages
Proc. SPIE 6473, Gallium Nitride Materials and Devices II, 64731S (8 February 2007);

Published in SPIE Proceedings Vol. 6473:
Gallium Nitride Materials and Devices II
Hadis Morkoc; Cole W. Litton, Editor(s)