Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200, Australia.
Nanotechnology. 2010 Jan 22;21(3):035604. doi: 10.1088/0957-4484/21/3/035604.
Straight, vertically aligned GaAs nanowires were grown on Si(111) substrates coated with thin GaAs buffer layers. We find that the V/III precursor ratio and growth temperature are crucial factors influencing the morphology and quality of buffer layers. A double layer structure, consisting of a thin initial layer grown at low V/III ratio and low temperature followed by a layer grown at high V/III ratio and high temperature, is crucial for achieving straight, vertically aligned GaAs nanowires on Si(111) substrates. An in situ annealing step at high temperature after buffer layer growth improves the surface and structural properties of the buffer layer, which further improves the morphology of the GaAs nanowire growth. Through such optimizations we show that vertically aligned GaAs nanowires can be fabricated on Si(111) substrates and achieve the same structural and optical properties as GaAs nanowires grown directly on GaAs(111)B substrates.
直的、垂直排列的 GaAs 纳米线在涂有薄 GaAs 缓冲层的 Si(111)衬底上生长。我们发现，V/III 前体比和生长温度是影响缓冲层形貌和质量的关键因素。双层结构，由在低 V/III 比和低温下生长的薄初始层和在高 V/III 比和高温下生长的层组成，对于在 Si(111)衬底上实现直的、垂直排列的 GaAs 纳米线至关重要。在缓冲层生长后进行高温原位退火步骤可以改善缓冲层的表面和结构特性，从而进一步改善 GaAs 纳米线生长的形态。通过这些优化，我们表明可以在 Si(111)衬底上制备垂直排列的 GaAs 纳米线，并实现与直接在 GaAs(111)B 衬底上生长的 GaAs 纳米线相同的结构和光学性质。
