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近年来,N2退火和O2退火均被用于激活p-GaN中的Mg受主以提高p-GaN中的空穴浓度。基于两种退火技术,系统地研究了N2退火和O2退火对LED样品电学性能及光学性能的影响。电流电压特性的测试结果显示,在较低温度(500℃)下O2退火就可以达到与N2高温退火(800℃)相似的电学特性。变温光致发光测试表明,N2高温退火会在InGaN量子阱中形成In团簇,In团簇作为深的势阱增加了对载流子的束缚,能够将载流子更好地局限在势阱中。然而In团簇形成的同时也伴随着大量位错的产生,使其InGaN量子阱中的位错密度大幅度提高,因此室温下N2退火样品的辐射复合效率低于O2退火样品的辐射复合效率。
In recent years, both N2 annealing and O2 annealing have been used to activate Mg acceptors in p-GaN to increase hole concentration in p-GaN. Based on two annealing techniques, the effects of N2 annealing and O2 annealing on the electrical and optical properties of LED samples were studied systematically. Current-voltage characteristics of the test results show that, at a lower temperature (500 ℃) O2 annealing can reach the N2 high-temperature annealing (800 ℃) similar to the electrical properties. The temperature-dependent photoluminescence (PL) photoluminescence measurements show that high-temperature N2 annealing will form In clusters in the InGaN quantum wells, and the In clusters as the deep potential wells increase the confinement of the carriers, which can better confine carriers in the potential well in. However, the formation of In clusters is also accompanied by a large number of dislocations, which greatly increase the dislocation density in the InGaN quantum wells. Therefore, the radiation recombination efficiency of N2 annealed samples at room temperature is lower than that of O2 annealed samples.