School of Information and Communication Technology, KTH-Royal Institute of Technology, Electrum 229, Kista SE-16440, Sweden.
Nanotechnology. 2013 Jun 7;24(22):225301. doi: 10.1088/0957-4484/24/22/225301. Epub 2013 Apr 30.
High material quality InP-based multilayer nanopillar (NP) arrays are fabricated using a combination of self-assembly of silica particles for mask generation and dry etching. In particular, the NP arrays are made from user-defined epitaxial multilayer stacks with specific materials and layer thicknesses. An additional degree of flexibility in the structures is obtained by changing the lateral diameters of the NP multilayer stacks. Pre-defined NP arrays made from InGaAsP/InP and InGaAs/InP NPs are then used to generate substrate-free nanodisks of a chosen material from the stack by selective etching. A soft-stamping method is demonstrated to transfer the generated nanodisks with arbitrary densities onto Si. The transferred nanodisks retain their smooth surface morphologies and their designed geometrical dimensions. Both InP and InGaAsP nanodisks display excellent photoluminescence properties, with line-widths comparable to unprocessed reference epitaxial layers of similar composition. The multilayer NP arrays are potentially attractive for broad-band absorption in third-generation solar cells. The high optical quality, substrate-free InP and InGaAsP nanodisks on Si offer a new path to explore alternative ways to integrate III-V on Si by bonding nanodisks to Si. The method also has the advantage of re-usable III-V substrates for subsequent layer growth.
使用二氧化硅颗粒自组装生成掩模和干法刻蚀相结合的方法，制造出了高质量的基于 InP 的多层纳米柱（NP）阵列。特别是，NP 阵列由具有特定材料和层厚度的用户定义的外延多层堆叠制成。通过改变 NP 多层堆叠的横向直径，可以在结构上获得额外的灵活性。然后，使用由 InGaAsP/InP 和 InGaAs/InP NPs 制成的预定义 NP 阵列，通过选择性刻蚀从堆叠中生成所选材料的无基底纳米盘。通过软压印方法，将生成的具有任意密度的纳米盘转移到 Si 上。转移的纳米盘保留其光滑的表面形貌和设计的几何尺寸。InP 和 InGaAsP 纳米盘均显示出优异的光致发光性能，其线宽与具有相似组成的未处理参考外延层相当。多层 NP 阵列有望在第三代太阳能电池中实现宽带吸收。在 Si 上的高光学质量、无基底 InP 和 InGaAsP 纳米盘为通过将纳米盘键合到 Si 上来探索在 Si 上集成 III-V 的替代方法提供了新途径。该方法还具有可重复使用的 III-V 衬底的优势，可用于后续层生长。
