利用等离子体辅助分子束外延设备(P-MBE)在m面的蓝宝石(m-Al2O3)衬底上制备了ZnO/Zn0.85Mg0.15O多量子阱.反射式高能电子衍射谱(RHEED)图样的原位观察表明,多量子阱结构是以二维模式生长的.从光致发光谱中可以看到ZnO/Zn0.85Mg0.15O多量子阱在室温仍具有明显的量子限域效应.在290K时阱宽为3nm的ZnO/Zn0.85Mg0.15O量子阱的发光峰位于3.405eV,通过变温发光谱研究了ZnO/Zn0.85Mg0.15O多量子阱的发光来源,在较低温度下为ZnO束缚激子辐射复合,而在较高温度下发光以自由激子为主.3nm的ZnO/Zn0.85Mg0.15O多量子阱束缚能为73meV.
The ZnO/Zn0.85Mg0.15O multiple quantum wells(MQWs)are fabricated on m-Al2O3 substrates by plasma-assisted molecular beam epitaxy (P-MBE) using a ZnMgO buffer layers. The reflection high-energy electron diffraction (RHEED) images indicate that the MQWs are of two-dimensional growth .The temperature dependent photoluminescence (PL) of the MQW also shows the quantum confine effect even at room temperature. The PL peak of 3nm MQW is 3.405 eV at 290 K.The PL spectrum in ZnO/Zn0.85Mg0.15O MQW is dominated by localized exciton emission at low temperatures, while the free exciton transition gradually dominates the spectrum at higher temperatures up to room temperature. The exciton binding energy in the 3 nm ZnO/Zn0.85Mg0.15O MQW is about 73 meV.