%A V. K. Malyutenko
%A O. Y. Malyutenko
%A A. V. Zinovchuk
%A ?. L. Zakhe?m
%J Proceedings of SPIE
%T Remote temperature mapping of high-power InGaN/GaN MQW
flip-chip design LEDs
%X We report on the study of heat 2D-distribution in InGaN LEDs with the stress made on local device overheating and
temperature gradients inside the structure. The MQW InGaN/GaN/sapphire blue LEDs are designed as bottom emitting
devices where light escapes the structure through the transparent GaN current spreading layer and sapphire substrate, whereas the LED structure with high-reflectivity Ni/Ag p-contact is bonded to the thermally conductive Si submount by a flip-chip method. The measurements are performed with an IR microscope operating in a time-resolved mode (3-5 ?m spectral range, <20 ?m spatial and 10 ?s temporal resolution), while scanning a heat emission map through a transparent sapphire substrate. We show how current crowding (which is difficult to avoid) causes a local hot region near the n-contact pads and affects the performance of the device at a high injection level.
%K InGaN/GaN, quantum wells, light-emitting diodes, thermal imaging.
%P 59411K-1
%V 5941
%D 2005
%I International society for optics and photonics
%L zu28341