Two-dimensional finite difference time domain (FDTD) simulations were performed for evaluating optical absorption enhancement and loss effects of triangular silver (Ag) nanowires embedded in silicon (Si) thin-film photovoltaic device structures. Near-bandgap absorption enhancement in Si was much larger than the reported values of other nanostructures from similar simulations. A nanowire with equal sides of 20 nm length showed 368-fold absorption enhancement whereas only 5× and 15× enhancement were reported for solid spherical and two-dimensional core-shell type nanostructures, respectively. Undesirable absorption loss in the metal of the nanowire was 3.55× larger than the absorption in Si which was comparable to the value reported for the spherical nanoparticle. Interestingly, as the height of the nanowire was increased to form a sharper tip, absorption loss showed a significant drop. For a nanowire with 20 nm base and 20 nm height, absorption loss was merely 1.91× larger than the absorption in Si at the 840 nm plasmon resonance. This drop could be attributed to weaker plasmon resonance manifested by lower metallic absorption in the spatial absorption map of the nanowire. However, absorption enhancement in Si was still large due to strong plasmonic fields at the sharper and longer tip, which was effective in enhancing absorption over a larger area in Si. Our work shows that the shape of a nanostructure and its optimization can significantly affect plasmonic absorption enhancement and loss performance in photovoltaic applications.

进行了二维有限时域时域（FDTD）仿真，以评估嵌入在硅（Si）薄膜光伏器件结构中的三角形银（Ag）纳米线的光吸收增强和损耗效应。Si中的带隙吸收增强远大于类似模拟中其他纳米结构的报道值。等边长为20 nm的纳米线显示了368倍的吸收增强，而对于固态球形和二维核-壳型纳米结构，分别仅报告了5倍和15倍增强。纳米线金属中不希望有的吸收损耗比Si中的吸收率大3.55倍，这与球形纳米粒子报道的值相当。有趣的是，随着纳米线的高度增加以形成尖锐的尖端，吸收损失显着下降。对于具有20 nm基底和20 nm高度的纳米线，其吸收损失仅比840 nm等离子体激元共振下Si中的吸收大1.91倍。该下降可归因于在纳米线的空间吸收图中金属离子吸收较低而表现出的等离子共振较弱。然而，由于在更尖且更长的尖端处的强等离子体场，Si中的吸收增强仍然很大，这有效地增强了在更大面积的Si中的吸收。我们的工作表明，纳米结构的形状及其优化可显着影响光伏应用中的等离子体吸收增强和损耗性能。比在840 nm等离子体激元共振下Si的吸收大91倍。该下降可归因于在纳米线的空间吸收图中金属离子吸收较低而表现出的等离子共振较弱。然而，由于在更尖且更长的尖端处的强等离子体场，Si中的吸收增强仍然很大，这有效地增强了在更大面积的Si中的吸收。我们的工作表明，纳米结构的形状及其优化可显着影响光伏应用中的等离子体吸收增强和损耗性能。比在840 nm等离子体激元共振下Si的吸收大91倍。该下降可以归因于在纳米线的空间吸收图中金属离子吸收较低而表现出的等离子体共振较弱。然而，由于在更尖且更长的尖端处的强等离子体场，Si中的吸收增强仍然很大，这有效地增强了在更大面积的Si中的吸收。我们的工作表明，纳米结构的形状及其优化可显着影响光伏应用中的等离子体吸收增强和损耗性能。由于在更尖和更长的尖端具有强大的等离子体场，Si的吸收增强仍然很大，这有效地增强了Si较大面积的吸收。我们的工作表明，纳米结构的形状及其优化可显着影响光伏应用中的等离子体吸收增强和损耗性能。由于在更尖且更长的尖端具有强大的等离激元场，Si中的吸收增强仍然很大，这有效地增强了Si中更大面积的吸收。我们的工作表明，纳米结构的形状及其优化可显着影响光伏应用中的等离子体吸收增强和损耗性能。