Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
Department of Electronic and Electrical Engineering, University College London , London WC1E 7JE, United Kingdom.
ACS Nano. 2017 Feb 28;11(2):1412-1418. doi: 10.1021/acsnano.6b06534. Epub 2017 Jan 17.
Nanoscale materials are promising for optoelectronic devices because their physical dimensions are on the order of the wavelength of light. This leads to a variety of complex optical phenomena that, for instance, enhance absorption and emission. However, quantifying the performance of these nanoscale devices frequently requires measuring absolute absorption at the nanoscale, and remarkably, there is no general method capable of doing so directly. Here, we present such a method based on an integrating sphere but modified to achieve submicron spatial resolution. We explore the limits of this technique by using it to measure spatial and spectral absorptance profiles on a wide variety of nanoscale systems, including different combinations of weakly and strongly absorbing and scattering nanomaterials (Si and GaAs nanowires, Au nanoparticles). This measurement technique provides quantitative information about local optical properties that are crucial for improving any optoelectronic device with nanoscale dimensions or nanoscale surface texturing.
纳米材料在光电子器件中具有广阔的应用前景，因为其物理尺寸与光的波长相当。这导致了各种复杂的光学现象，例如增强吸收和发射。然而，要量化这些纳米尺度器件的性能，通常需要测量纳米尺度的绝对吸收，而令人惊讶的是，目前还没有直接实现这一目标的通用方法。在这里，我们提出了一种基于积分球的方法，但对其进行了改进，以实现亚微米级的空间分辨率。我们通过使用该方法测量各种纳米尺度系统（包括弱吸收和强吸收、散射纳米材料（硅和砷化镓纳米线、金纳米粒子）的不同组合）的空间和光谱吸收率分布，来探索该技术的极限。这种测量技术提供了关于局部光学性质的定量信息，这对于改进任何具有纳米尺寸或纳米尺度表面形貌的光电设备至关重要。
