具金屬奈米結構的太陽電池的模擬研究

Abstract

本論文中，我們利用名為COMSOL的模擬工具來計算有金屬奈米結構之太陽電池的光吸收和載子傳輸問題。此太陽電池包含了p型氮化鎵層、n型氮化鎵層和中間的i型氮化銦鎵吸收層。這裡所用的光源是AM1.5G的太陽光譜。我們利用金屬奈米結構去激發表面電漿子進而增加太陽電池的光吸收。由於表面電漿子的共振頻率取決於金屬與介質交界面的幾何形狀，故控制增加光吸收的頻段應是可行的。為了進一步了解表面電漿子和繞射如何影響太陽電池的光吸收，我們改變奈米金屬結構的形狀與排列週期，並藉數值模擬，比較有奈米金屬結構與無奈米金屬結構的情形下的太陽電池光吸收的程度。最後，我們模擬太陽電池的光電流與效率在表面電漿子與繞射的影響下所產生的增益。

In this thesis, we use the simulation tool COMSOL to calculate the light absorption and carrier transport of the solar cells with metallic nanostructures. The solar cell structure consists of a p-GaN layer, a n-GaN layer, and in between a i-InGaN absorption layer. The light source adopted is the AM1.5G solar spectrum. We use the metallic nanostructures for exciting surface plasmons to enhance the light absorption of solar cells. Because the resonance frequencies of surface plasmons depend on the geometry of the metal-dielectric interface, it is feasible to control the enhancement of light absorption at a desired wavelength. To further understand the influences of surface plasmon and diffraction on the light absorption of solar cells, we change the shape and period of metallic nanostructures to see the effect. Through numerical simulation, we compare the light absorption for the solar cell with metallic nanostructures to that for the solar cell without nanostructures. Finally, we numerically investigate the enhancement of photocurrent and efficiency for the solar cells with the aid of the surface plasmons and diffraction effects.