Self-Optimizing Photoelectrochemical Growth of Nanopatterned Se-Te Films in Response to the Spectral Distribution of Incident Illumination.
Self-Optimizing Photoelectrochemical Growth of Nanopatterned Se-Te Films in Response to the Spectral Distribution of Incident Illumination.
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纳米图案 Se-Te 薄膜响应入射照明光谱分布的自优化光电化学生长。
DOI：
10.1021/acs.nanolett.5b03137
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发表时间：
2015
期刊：
影响因子：
10.8
通讯作者：
N. Lewis
中科院分区：
文献类型：
--
作者：
Azhar I. Carim;Nicolas A. Batara;Anjali Premkumar;H. Atwater;N. Lewis
Se-Te 薄膜的光电化学生长会自发地产生高度有序的纳米级层状形态，其周期性可以通过在沉积过程中改变照明波长来调节。本文通过确定响应于定制的光谱照明分布的光电镀Se-Te膜的形态来进一步表征该现象。 Se-Te 薄膜在四种不同光源的照射下生长，具有相似的平均波长，但光谱带宽跨越几个数量级，但都产生了相似的结构，这些结构具有通过傅里叶分析定量识别的单一、共同的周期性。使用两个窄带源（其平均波长相差数百纳米）同时照射的薄膜沉积，导致在单独使用任一源时观察到的周期之间仅具有单一周期性中间的结构。这个单一的周期性可以通过操纵两个源的相对强度来改变。将全波电磁效应与蒙特卡罗生长模拟相结合的迭代模型，并且仅考虑沉积过程中基本的光-材料相互作用，与实验观察到的形态一致。理想化层状阵列中光吸收和浓度的模拟，结合所有可用数据，还表明，纳米级图案周期性的自我优化，导致三维结构中界面光吸收各向异性的最大化，与观察到的此类薄膜的生长过程一致。
Photoelectrochemical growth of Se-Te films spontaneously produces highly ordered, nanoscale lamellar morphologies with periodicities that can be tuned by varying the illumination wavelength during deposition. This phenomenon has been characterized further herein by determining the morphologies of photoelectrodeposited Se-Te films in response to tailored spectral illumination profiles. Se-Te films grown under illumination from four different sources, having similar average wavelengths but having spectral bandwidths that spanned several orders of magnitude, all nevertheless produced similar structures which had a single, common periodicity as quantitatively identified via Fourier analysis. Film deposition using simultaneous illumination from two narrowband sources, which differed in average wavelength by several hundred nanometers, resulted in a structure with only a single periodicity intermediate between the periods observed when either source alone was used. This single periodicity could be varied by manipulating the relative intensity of the two sources. An iterative model that combined full-wave electromagnetic effects with Monte Carlo growth simulations, and that considered only the fundamental light-material interactions during deposition, was in accord with the morphologies observed experimentally. Simulations of light absorption and concentration in idealized lamellar arrays, in conjunction with all of the available data, additionally indicated that a self-optimization of the periodicity of the nanoscale pattern, resulting in the maximization of the anisotropy of interfacial light absorption in the three-dimensional structure, is consistent with the observed growth process of such films.