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采用光辅助金属有机化学气相沉积(MOCVD)技术在(0001)蓝宝石衬底上制备了ZnO薄膜。通过X射线衍射、透射光谱和霍尔测试等研究了光照对MOCVD法制备的ZnO薄膜的影响。实验结果表明,引入光辅助后制备的ZnO薄膜,其结晶质量和光学质量均得到改善。分析认为,这主要是由于光辅助有助于提高锌有机源的分解效率,并且高能量的光子可为反应吸附的原子提供足够高的激活能,从而易于其迁移到合适的晶格位置所致。同时我们还发现,有光照和无光照条件下制备的ZnO薄膜均呈n型导电,但有光照条件下制备的ZnO薄膜具有更低的本底载流子浓度,这将为日后通过降低自补偿实现p型掺杂提供一个很好的解决办法。 相似文献
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采用低压金属有机物化学气相沉积(LP-MOCVD)技术在Ga As(001)衬底上制备Ga Sb量子点,研究了反应室压强对改善Ga Sb/Ga As量子点形貌各向异性的影响。通过Sb表面处理方法,在Ga As衬底上形成低表面能的Sb-Sb浮层,实现以界面失配(IMF)生长模式对Ga Sb量子点诱导生长。用原子力显微镜(AFM)对各样品的量子点形貌进行了表征,结果表明Ga Sb量子点形貌各向异性明显且沿[110]方向拉长。在压强条件为10 k Pa时,IMF生长模式导致不对称岛的长宽比大于3,由于低能量(111)侧面的存在,Ga Sb量子点优先沿[110]方向生长而不是与之垂直的[110]方向。压强降低至4 k Pa时量子点密度增大为8. 3×109cm-2,量子点形貌转变为对称的半球形且长宽比约为1。低的压强降低了吸附原子的扩散激活能从而增大了扩散长度,可以有效改善Ga Sb量子点的各向异性。 相似文献
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采用金属有机化学气相沉积(MOCVD)技术在蓝宝石衬底上制备出晶体质量较好的透明导电的ZnO/Au/ZnO(ZAZ)多层膜,其中,Au夹层是通过射频磁控溅射的方法获得。通过对Au夹层进行不同温度的退火处理,研究了Au层退火温度对ZAZ多层膜的结构特性、电学性能和光学特性的影响。利用原子力显微镜(AFM)、扫描电子显微镜(SEM)、X射线衍射(XRD)仪、霍尔效应测试和透射谱分析等测试手段对ZAZ多层膜的性质进行了分析。测试结果表明,在200 ℃下对Au夹层进行快速退火处理,多层膜的结构、电学和光学性质达到最优,表面等离子体效应也更明显。其中,XRD(002)衍射峰的半高宽为0.14°,电阻率为2.7×10-3 Ω·cm,载流子浓度为1.07×1020 cm-3,可见光区平均透过率为75.3%。 相似文献
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Electrically Pumped Ultraviolet Random Lasing from p-ZnO:As Based on p-ZnO/N-GaN Heterojunction
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p-ZnO:As is prepared by the GaAs interlayer doping method. The potential applications of p-ZnO:As are evaluated by applying it into the construction of a p-ZnO/n-GaN heterojunction, though its hall, electrochemical capacitance-voltage and photoluminescence results show a hole concentration at the level of -10^17 cm-3 and a good optical quality. Ultraviolet random lasing is detected from the studied device under forward bias. Specific lasing modes are confirmed to originate from p-ZnO:As by further introducing the p-ZnO/MgO/n-GaN het- erostructure. The resulting random lasing phenomena demonstrate the promising prospects in device application of p-ZnO:As fabricated by using our methods. 相似文献
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The initial growth stage of GaSb on GaAs(001) by low pressure metal–organic chemical vapor deposition(MOCVD)is investigated. The dependence of the nucleation on growth temperature, growth pressure, and vapor V/III ratio is studied by means of atomic force microscopy. The nucleation characteristics include the island density, size, and size uniformity distribution. The nucleation mechanism is discussed by the effects of growth temperature, growth pressure, and vapor V/III ratio on the density, size, and size uniformity of GaSb islands. With the growth temperature increasing from 500℃ to610℃ and the growth pressure increasing from 50 mbar to 1000 mbar(1 mbar = 105Pa), the island density first increases and then decreases; with the V/III ratio increasing from 0.5 to 3, the trend is contrary. 相似文献
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