School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Nano Lett. 2011 Nov 9;11(11):4515-9. doi: 10.1021/nl1044605. Epub 2011 Oct 3.
(In, Ga)N nanostructures show great promise as the basis for next generation LED lighting technology, for they offer the possibility of directly converting electrical energy into light of any visible wavelength without the use of down-converting phosphors. In this paper, three-dimensional computation of the spatial distribution of the mechanical and electrical equilibrium in nanoheterostructures of arbitrary topologies is used to elucidate the complex interactions between geometry, epitaxial strain, remnant polarization, and piezoelectric and dielectric contributions to the self-induced internal electric fields. For a specific geometry-nanorods with pyramidal caps-we demonstrate that by tuning the quantum well to cladding layer thickness ratio, h(w)/h(c), a minimal built-in electric field can be experimentally realized and canceled, in the limit of h(w)/h(c) = 1.28, for large h(c) values.
(In、Ga)N 纳米结构有望成为下一代 LED 照明技术的基础,因为它们提供了将电能直接转化为任何可见波长光的可能性,而无需使用下转换荧光粉。在本文中,通过对任意拓扑纳米异质结构的机械和电平衡的空间分布进行三维计算,阐明了几何形状、外延应变、剩余极化以及压电和介电对自诱导内部电场的贡献之间的复杂相互作用。对于特定的几何形状-带有金字塔帽的纳米棒-我们证明,通过调整量子阱到包层厚度比 h(w)/h(c),可以在 h(w)/h(c) = 1.28 的极限下,对于大的 h(c) 值,实验上实现并抵消最小的内置电场。