利用超寬頻激發探測光譜研究PCPDTBT:PCBM太陽能電池之載子超快動力學

Abstract

聚[2,1,3-苯並噻二唑-4,7-二基[4,4-雙(2-乙基己基)-4H-環戊並[2,1-B:3,4-B']二噻吩-2,6-二基]] (PCPDTBT):[ 6,6 ]苯基C61丁酸甲酯 (PCBM) 太陽能電池因為其製作成本低、有效吸收可見光波段、能量轉換效率可利用添加物調整而受到廣泛的重視◦然而PCPDTBT:PCBM的薄膜組成以及樣貌也會影響能量轉換效率◦最近日本電氣通信大學的Vohra教授成功利用微乳液技術製作出PCPDTBT:PCBM 混和的奈米粒子，並將其作為太陽能電池的主動層◦發現混和奈米粒子元件的能量轉換效率較沒有奈米粒子的元件高◦ 我們利用自行架設的NOPA (non-collinear optical parametric amplifier)系統研究PCPDTBT:PCBM有混合奈米粒子以及無奈米粒子太陽能電池元件的超快動力學行為，希望能釐清奈米結構改善能量轉換效率的機制，並且有助於太陽能電池技術的發展◦

Poly[2,6-(4,4-bis-(2-ethylhexyl)-4h-cyclopenta[2,1-b;3.4-b'] ditho–phene)-alt-4,7-(2,1,3-benzo-thiadiazole)] (PCPDTBT):[6,6]-phenyl-C61- butyric acid methyl ester (PCBM) solar cells have been attracting great attention due to its low price in production, efficient absorption of visible light, adjustable power conversion efficiency (PCE) by additives. However, formation and morphology of PCPDTBT:PCBM thin films seriously affect the PCE. Recently, Prof. Vohra of University of Electro-Communications (UEC) produced PCPDTBT:PCBM blend nanoparticles by miniemulsion technique successfully, and used it as the active layer of solar cell. The PCE of PCPDTBT:PCBM blend nanoparticle solar cell was found to be higher than the one without nanoparticles. We have used a homemade non-collinear optical parametric amplifier (NOPA) system to study the ultrafast dynamics of PCPDTBT:PCBM solar cell devices with nanoparticles and without nanoparticles. Hope to figure out the mechanism with which the nanoparticles structure improves PCE, and provide some key information for further improvement of the PCPDTBT:PCBM solar cell devices.