采用 Al N插入层技术在 Si(1 1 1 )衬底上实现无微裂 Ga N MOCVD生长 .通过对 Ga N外延层的 a,c轴晶格常数的测量 ,得到了 Ga N所受张应力与 Al N插入层厚度的变化关系 .当 Al N厚度在 7～ 1 3nm范围内 ,Ga N所受张应力最小 ,甚至变为压应力 .因此 ,Ga N微裂得以消除 .同时研究了 Al N插入层对 Ga N晶体质量的影响 ,结果表明 ,许多性能相比于没有 Al N插入层的 Ga
Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor deposition method.The X-ray double-crystal diffraction rocking curve measurements show the full-width half maximum of 180″ and 185″ for (0002) symmetric reflection and (10 12) skew reflection,respectively.A room temperature mobility of 850cm2/(V·s) is obtained for a 3μm thick GaN film.Gain guided and ridge geometry waveguide laser diodes are fabricated with cleaved facet mirrors at room temperature under pulse current injection.The lasing wavelength is 405 9nm.A threshold current density of 5kA/cm2 and an output light power over 100mW are obtained for ridge geometry waveguide laser diodes.
