School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Korea.
ACS Nano. 2014 Mar 25;8(3):3080-7. doi: 10.1021/nn500646j. Epub 2014 Feb 21.
Tunable surface morphology in III-V semiconductor nanomembranes provides opportunities to modulate electronic structures and light interactions of semiconductors. Here, we introduce a vacuum-induced wrinkling method for the formation of ordered wrinkles in InGaAs nanomembranes (thickness, 42 nm) on PDMS microwell arrays as a strategy for deterministic and multidirectional wrinkle engineering of semiconductor nanomembranes. In this approach, a vacuum-induced pressure difference between the outer and inner sides of the microwell patterns covered with nanomembranes leads to bulging of the nanomembranes at the predefined microwells, which, in turn, results in stretch-induced wrinkle formation of the nanomembranes between the microwells. The direction and geometry of the nanomembrane wrinkles are well controlled by varying the PDMS modulus, depth, and shape of microwells, and the temperature during the transfer printing of nanomembrane onto heterogeneous substrates. The wrinkling method shown here can be applied to other semiconductor nanomembranes and may create an important platform to realize unconventional electronic devices with tunable electronic properties.
在 III-V 族半导体纳米薄膜中，可调谐的表面形态为调节半导体的电子结构和光相互作用提供了机会。在这里，我们介绍了一种真空诱导的褶皱形成方法，用于在 PDMS 微井阵列上的 InGaAs 纳米薄膜（厚度为 42nm）中形成有序的褶皱，这是一种用于半导体纳米薄膜的确定性和多方向褶皱工程的策略。在这种方法中，覆盖有纳米薄膜的微井图案的外表面和内表面之间的真空诱导压力差导致纳米薄膜在预定义的微井处凸起，这反过来又导致纳米薄膜在微井之间产生拉伸诱导的褶皱形成。通过改变 PDMS 的模量、微井的深度和形状以及在将纳米薄膜转移印刷到异质衬底上时的温度，可以很好地控制纳米薄膜褶皱的方向和几何形状。这里展示的褶皱方法可以应用于其他半导体纳米薄膜，并可能为实现具有可调谐电子特性的非常规电子设备创建一个重要平台。
