首次报道了用不同浓度的Al离子注入于蓝宝石衬底上的GaN薄膜(注入能量为500keV、注入浓度为1014～1015 cm-2), 在做了不同温度和不同时间的快速热退火处理以及常规热退火处理后,在12K下用He-Cd 激光(325nm)激发得到其发射谱.结果显示, 经大剂量Al注入后的样品,其光致发光谱中3.45eV的带边激子发光以及2.9 ～ 3.3eV的4个声子伴随峰消失.此表明大剂量Al注入对GaN的晶体结构造成严重的损伤,以致本征发光消失.经1014cm-2剂量Al注入后的样品,在N2气氛中退火处理后,2.2eV缺陷发光峰得到了一定程度的恢复.而且,经常规退火处理后,此发射峰比快速退火处理的样品发射峰恢复得更好(其积分光强高3倍).相似的结果亦显示于1015 cm-2 浓度的Al 注入的样品.2.2eV 黄色荧光源于GaN的缺陷(如Ga空位(VGa), 或VGa-H2,或VGa-ON 复合体),其能级位于价带顶以上约1.1eV处.荧光发射可以来自"导带-缺陷能级"的跃迁,也可能来自浅施主(如N位O,能级位于导带下～10 meV)至上述缺陷能级之间的跃迁.I-V 测量显示,Al的注入区成为～ 1012 Ω*cm-1高阻膜,这表明Al的注入可能产生了某种深的电子陷阱,由于电子陷阱可俘获导带电子,导致发光猝灭.而退火可使与黄色荧光相关的缺陷得到部分恢复,因而2.2eV发射峰有所恢复.
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