運用奈米粒子及奈米球微影技術提升矽晶太陽能電池光補獲的特性

Abstract

本論文為研究矽晶太陽能電池的抗反射結構及光轉移的機制。論文內容可分成三部份：（1）奈米粒子_Silica（2）奈米蜂巢式結構（3）奈米螢光粉YVO4：Bi3+：Eu3+。 （1）奈米粒子_Silica：將奈米粒子利用旋轉塗佈法，均勻沉積於多晶矽電池表面，並透過奈米粒子的光散射特性，進一步改量原有電池的抗反射率。經由奈米粒子的散射機制，可得到良好UV跟NIR波段的抗反射效果。當奈米粒子濃度及旋塗參數最佳化時，則電池試片可由原本的11%，增加至12.3%。 （2）奈米蜂巢式結構：利用奈米球微影技術製造氧化鋅蜂巢式結構，並將此結構作落在單晶矽電池的粗糙化結構表面。發現此結構從UV到NIR皆具有良好抗反射效果。當氧化鋅濃度及蜂巢式結構尺寸最佳化時，可將原有電池試片效率由15.6%增至16.6%。 （3）奈米螢光粉YVO4：Bi3+：Eu3+：將無機奈米螢光粉旋塗於單晶矽電池表面，利用其光轉移機制及粒子散射特性，可成功將原有試片的短路電流密度提升4%，並將整體電池效率提高了0.7%。證實透過發光材料的光轉移機制，可提升電池試片於UV波段的量子效率。

This thesis is focus on the anti-reflection and luminescent down-shifting property of silicon solar cell. The content is divided into three parts：(1) Nanoparticles_Silica (2) Nano-Honeycomb Structure Layer (3) Nano-Phosphors_YVO4：Bi3+：Eu3+. Part one: In this study, silica nanospheres dispersed in a surfactant solution were spin-coated on commercially available silicon solar cells to form colloidal crystals on the surface. This self-assembled nanoparticle layer served as an anti-reflection (AR) layer for solar cell devices. The self-assembled layer exhibits excellent anti-reflection properties in the UV and NIR wavelength regions. We also showed that the overall conversion efficiency of polycrystalline Si solar cells coated with the silica nanospheres was increased from 11% to 12.3% when using optimized spin-coating parameters and nanoparticle concentrations. Part two: This experiment demonstrates the process for manufacturing a ZnO honeycomb sub-wavelength structure using nanosphere lithography technology exhibiting excellent anti-reflection properties from the UV to NIR wavelength regions. This honeycomb nanostructure, combined with commercially available crystalline Si solar cells, show substantially improved conversion efficiency from 15.6% to 16.6% using optimized honeycomb sizes and precursor concentrations of ZnO. The present work develops an unsophisticated and economical technique suitable for industrial applications in producing a uniform and low-reflective texture. Part three: The colloids of YVO4 nanoparticles on micro-textured Si surface are demonstrated to have promising potential for efficient solar spectrum utilization in crystalline Si solar cells. The solar cells showed an enhancement of 4% in short-circuit current density and approximately 0.7% in power conversion efficiency when coated with YVO4 nanoparticles. The properties of cells integrated with YVO4 nanoparticles were characterized to identify the role of YVO4 in improved light harvesting. The current experiments conclude that the colloids of YVO4 nanoparticles not only act as luminescent down-shifting centers in the ultraviolet region but also serve as an anti-reflection coating for enhancing the light absorption in the measured spectral regime.