Liu Ting, Zhang Jicai, Su Xujun, Huang Jun, Wang Jianfeng, Xu Ke
Platform for Characterization and Test, Suzhou Institute of Nano-tech and Nano-bionics, CAS, Suzhou, 215123, China.
Suzhou Nanowin Science and Technology Co., Lt/d, Suzhou, 215123, China.
Sci Rep. 2016 May 17;6:26040. doi: 10.1038/srep26040.
Wurtzite AlN is widely used for deep ultraviolet optoelectronic devices (DUV), which are generally grown along the [0001]-direction of the wurtzite structure on currently available substrates. However, huge internal electrostatic fields are presented within the material along [0001] axis induced by piezoelectric and spontaneous polarization, which has limited the internal quantum efficiency of AlN based DUV LEDs dramatically. The internal fields can be strongly reduced by changing the epitaxial growth direction from the conventional polar c-direction into less polar crystal directions. Twinned crystal is a crystal consisting of two or more domains with the same crystal lattice and composition but different crystal orientations. In other words, twins can be induced to change crystal directions. In this work we demonstrated that the epitaxial growth of () semi-polar AlN on (0001) AlN by constructing () and () twin structures. This new method is relative feasible than conventional methods and it has huge prospect to develop high-quality semi-polar AlN.
纤锌矿型氮化铝（Wurtzite AlN）广泛应用于深紫外光电器件（DUV），这类器件通常在现有衬底上沿纤锌矿结构的[0001]方向生长。然而，由于压电极化和自发极化，材料内部沿[0001]轴存在巨大的内部静电场，这极大地限制了基于AlN的深紫外发光二极管（DUV LEDs）的内部量子效率。通过将外延生长方向从传统的极性c方向改变为极性较小的晶体方向，可以显著降低内部电场。孪晶是一种由两个或多个具有相同晶格和成分但晶体取向不同的畴组成的晶体。换句话说，可以诱导孪晶来改变晶体方向。在这项工作中，我们通过构建（）和（）孪晶结构，证明了在（0001）AlN上外延生长（）半极性AlN。这种新方法比传统方法相对可行，并且在开发高质量半极性AlN方面具有巨大的前景。
