Zhao Tianze, Gao Yanze, Shi Rui, Li Zhuo, Shi Qingfeng
School of Optics and Photonics, Beijing Institute of Technology, Zhongguancun South Street 5, Beijing 100081, China.
Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, Zhongguancun South Street 5, Beijing 100081, China.
Materials (Basel). 2022 Jul 7;15(14):4778. doi: 10.3390/ma15144778.
Nanoparticle aggregate structures allow for efficient photon capture, and thus exhibit excellent optical absorption properties. In this study, a model of randomly distributed nanochain aggregates on silicon substrates is developed and analyzed. The Gaussian, uniform, and Cauchy spatial distribution functions are used to characterize the aggregate forms of the nanochains and their morphologies are realistically reconstructed. The relationships between the structural parameters (thickness and filling factor), equivalent physical parameters (density, heat capacity, and thermal conductivity), and visible absorptivity of the structures are established and analyzed. All the above-mentioned parameters exhibit extreme values, which maximize the visible-range absorption; these values are determined by the material properties and nanochain aggregate structure. Finally, Al nanochain aggregate samples are fabricated on Si substrates by reducing the kinetic energy of the metal vapor during deposition. The spectral reflection characteristics of the samples are studied experimentally. The Spearman correlation coefficients for the calculated spectral absorption curves and those measured experimentally are higher than 0.82, thus confirming that the model is accurate. The relative errors between the calculated visible-range absorptivities and the measured data are less than 0.3%, further confirming the accuracy of the model.
纳米颗粒聚集体结构能够实现高效的光子捕获，因此具有优异的光吸收特性。在本研究中，建立并分析了硅衬底上随机分布的纳米链聚集体模型。采用高斯、均匀和柯西空间分布函数来表征纳米链的聚集形式，并逼真地重构了它们的形态。建立并分析了结构参数（厚度和填充因子）、等效物理参数（密度、热容量和热导率）与结构的可见光吸收率之间的关系。上述所有参数均呈现出极值，这些极值使可见光范围的吸收最大化；这些值由材料特性和纳米链聚集体结构决定。最后，通过在沉积过程中降低金属蒸汽的动能，在硅衬底上制备了铝纳米链聚集体样品。对样品的光谱反射特性进行了实验研究。计算得到的光谱吸收曲线与实验测量曲线的斯皮尔曼相关系数高于0.82，从而证实了该模型的准确性。计算得到的可见光范围吸收率与测量数据之间的相对误差小于0.3%，进一步证实了该模型的准确性。
