Light emitter diodes (LEDs) are typical layered structures composed of different film materials. During the fabrication of LEDs, the mechanical stresses induced in the thin films due to misfit in lattice constants and difference in thermal expansion coefficients between adjacent layers will lead to dislocations and defects in structures such as hillocks, cracks and voids, which will not only significantly reduce the strength of structures but also reduce the efficiency and stability of LEDs. In this article, the influences of misfit strain, dislocation and thermal stresses due to difference in thermal expansion coefficients on total mechanical stresses of multilayered heterostructures are considered. A simple and powerful modified shear lag method is proposed to evaluate the mechanical stresses in LEDs subjected to thermal annealing treatment. Moreover, the influences of quantum-well structure and indium content on the mechanical stresses and optoelectronic characteristics of LEDs are also evaluated and discussed.
|Number of pages||9|
|Journal||Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an|
|Publication status||Published - 2008 Jan 1|
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