Pritom Yeasin Arafat, Sikder Dipayon Kumar, Zaman Sameia, Hossain Mainul
Department of Electrical and Electronic Engineering, University of Dhaka Dhaka 1000 Bangladesh
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology Dhaka 1205 Bangladesh.
Nanoscale Adv. 2023 Aug 24;5(18):4986-4995. doi: 10.1039/d3na00436h. eCollection 2023 Sep 12.
Sub-wavelength plasmonic light trapping nanostructures are promising candidates for achieving enhanced broadband absorption in ultra-thin silicon (Si) solar cells. In this work, we use finite-difference time-domain (FDTD) simulations to demonstrate the light harvesting properties of periodic and parabola shaped Si nanostructures, decorated with metallic gold (Au) nanoparticles (NPs). The active medium of absorption is a 2 μm thick crystalline-silicon (c-Si), on top of which the parabolic nanotextures couple incident sunlight into guided modes. The parabola shape provides a graded refractive index profile and high diffraction efficiencies at higher order modes leading to excellent antireflection effects. The Au NPs scatter light into the Si layer and offer strong localized surface plasmon resonance (LSPR) resulting in broadband absorption with high conversion efficiency. For wavelengths () ranging between 300 nm and 1600 nm, the structure is optimized for maximum absorption by adjusting the geometry and periodicity of the nanostructures and the size of the Au NPs. For parabola coated with 40 nm Au NPs, the average absorption enhancements are 7% (between = 300 nm and 1600 nm) and 28% (between = 800 nm and 1600 nm) when compared with bare parabola. Furthermore, device simulations show that the proposed solar cell can achieve a power conversion efficiency (PCE) as high as 21.39%, paving the way for the next generation of highly efficient, ultra-thin and low-cost Si solar cells.
亚波长等离子体光捕获纳米结构是实现超薄硅（Si）太阳能电池宽带吸收增强的有前途的候选材料。在这项工作中，我们使用时域有限差分（FDTD）模拟来展示周期性和抛物线形硅纳米结构的光捕获特性，这些结构装饰有金属金（Au）纳米颗粒（NPs）。吸收的活性介质是一个2μm厚的晶体硅（c-Si），抛物线形纳米纹理在其顶部将入射太阳光耦合到导模中。抛物线形状提供了渐变的折射率分布，并在高阶模式下具有高衍射效率，从而产生优异的抗反射效果。金纳米颗粒将光散射到硅层中，并提供强烈的局域表面等离子体共振（LSPR），从而实现具有高转换效率的宽带吸收。对于波长在300nm至1600nm之间的光，通过调整纳米结构的几何形状、周期性和金纳米颗粒的尺寸，对结构进行优化以实现最大吸收。对于涂覆有40nm金纳米颗粒的抛物线，与裸抛物线相比，平均吸收增强分别为7%（在300nm至1600nm之间）和28%（在800nm至1600nm之间）。此外，器件模拟表明，所提出的太阳能电池可以实现高达21.39%的功率转换效率（PCE），为下一代高效、超薄和低成本的硅太阳能电池铺平了道路。
