利用電激螢光影像分析多接面太陽能電池之光學特性

Abstract

本論文研究在紅外線雷射照射下三接面太陽能電池的空間解析電激螢光影像。在本研究中，我們使用電激螢光影像、電激螢光光譜以及電場調製反射光譜來研究第一層子電池與第二層子電池的光學特性。當入射的紅外線雷射光其能量小於第一層子電池的能隙，但卻大於第二層子電池的能隙時，第一層子電池的電激螢光光強度會變弱。由電場調製反射光譜結果可知，入射的雷射光使得第一層子電池的內建電場變大。隨著入射的雷射光瓦數越來越大時，電激螢光光強度成指數遞減。當紅外線雷射光照射在第二層子電池時，會產生光電壓導致第一層子電池的外加偏壓減少，使得電激螢光光強度變弱。

Spatially-resolved electroluminescence (EL) images in triple-junction solar cells have been investigated under irradiation of the IR laser. The EL image, EL spectra, and ER spectra have been used to investigate the optical properties between the top subcell and the middle subcell. Upon irradiating the IR laser with energy below the bandgap of the top subcell, but above the middle subcell, the EL intensity of the top subcell is quenched. From the result of ER spectra, the build-in electric field of the top subcell increases under irradiation of the IR laser. With increasing the irradiation of the IR laser, the EL intensity quenches exponentially. We find the EL intensity of the top subcell is quenched owing to the photovoltage generated by the irradiation of the IR laser and the coupling effect between the top subcell and the middle subcell.