Department of Electronic and Electrical Engineering , University College London , London WC1E 7JE , United Kingdom.
Department of Physics and Astronomy , University of Sheffield , Sheffield S3 7RH , United Kingdom.
Nano Lett. 2018 Jul 11;18(7):4206-4213. doi: 10.1021/acs.nanolett.8b01100. Epub 2018 Jun 18.
Semiconductor nanowire-based devices are among the most promising structures used to meet the current challenges of electronics, optics and photonics. Due to their high surface-to-volume ratio and excellent optical and electrical properties, devices with low power, high efficiency and high density can be created. This is of major importance for environmental issues and economic impact. Semiconductor nanowires have been used to fabricate high performance devices, including detectors, solar cells and transistors. Here, we demonstrate a technique for transferring large-area nanowire arrays to flexible substrates while retaining their excellent quantum efficiency in emission. Starting with a defect-free self-catalyzed molecular beam epitaxy (MBE) sample grown on a Si substrate, GaAs core-shell nanowires are embedded in a dielectric, removed by reactive ion etching and transferred to a plastic substrate. The original structural and optical properties, including the vertical orientation, of the nanowires are retained in the final plastic substrate structure. Nanowire emission is observed for all stages of the fabrication process, with a higher emission intensity observed for the final transferred structure, consistent with a reduction in nonradiative recombination via the modification of surface states. This transfer process could form the first critical step in the development of flexible nanowire-based light-emitting devices.
基于半导体纳米线的器件是满足当前电子学、光学和光子学挑战的最有前途的结构之一。由于其高的比表面积和优异的光学和电学性能，可以制造出具有低功耗、高效率和高密度的器件。这对于环境问题和经济影响非常重要。半导体纳米线已被用于制造高性能器件，包括探测器、太阳能电池和晶体管。在这里，我们展示了一种将大面积纳米线阵列转移到柔性衬底上的技术，同时保持其在发射时的优异量子效率。从在 Si 衬底上生长的无缺陷自催化分子束外延（MBE）样品开始，GaAs 核壳纳米线被嵌入电介质中，通过反应离子刻蚀去除，并转移到塑料衬底上。纳米线的原始结构和光学性质，包括垂直取向，在最终的塑料衬底结构中得以保留。在整个制造过程的所有阶段都观察到了纳米线的发射，最终转移结构的发射强度更高，这与通过表面态的修饰减少非辐射复合一致。这种转移过程可能是开发基于柔性纳米线的发光器件的关键的第一步。
