Wang Baomin, Stevens Erica, Leu Paul W
Opt Express. 2014 Mar 10;22 Suppl 2:A386-95. doi: 10.1364/OE.22.00A386.
We studied the influence of geometric parameters on the optical absorption of gallium arsenide (GaAs) nanocone and nanowire arrays via finite difference time domain simulations. We optimized the structural parameters of the nanocone and nanowire arrays to maximize the ultimate efficiency across a range of lengths from 100 to 1000 nm. Nanocone arrays were found to have improved solar absorption, short-circuit current density, and ultimate efficiencies over nanowire arrays for a wide range of lengths. Detailed simulations reveal that nanocones have superior absorption due to reduced reflection from their smaller tip and reduced transmission from their larger base. Breaking the vertical mirror symmetry of nanowires results in a broader absorption spectrum such that overall efficiencies are enhanced for nanocones. We also evaluated the electric field intensity, carrier generation and angle-dependent optical properties of nanocones and nanowires. The carrier generation in nanocone arrays occurs away from the surface and is more uniform over the entire structure, which should result in less recombination losses than in nanowire arrays.
我们通过时域有限差分模拟研究了几何参数对砷化镓（GaAs）纳米锥和纳米线阵列光吸收的影响。我们优化了纳米锥和纳米线阵列的结构参数，以在100至1000 nm的一系列长度范围内最大化极限效率。发现在很宽的长度范围内，纳米锥阵列比纳米线阵列具有更好的太阳能吸收、短路电流密度和极限效率。详细的模拟表明，纳米锥具有优异的吸收性能，这是由于其较小的尖端反射减少以及较大的基部透射减少。打破纳米线的垂直镜面对称性会导致更宽的吸收光谱，从而提高纳米锥的整体效率。我们还评估了纳米锥和纳米线的电场强度、载流子产生以及角度相关的光学性质。纳米锥阵列中的载流子产生发生在远离表面的位置，并且在整个结构上更加均匀，这应该比纳米线阵列导致更少的复合损失。
