Adding PC71BM into the Photoactive Layer to Improve the Performance of Organic Ternary Solar Cells

• Main Authors: LUO,JIN-WEN, 羅錦文
• Other Authors: HSU,FANG-CHI
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/8555b9

碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 108 === In this study, we use the inverted organic solar cell structure. A different weight ratio of PC71BM was added ino the polymer donor PBDB-T and the polymer acceptor N2200 forming a ternary organic solar cell. The short-circuit current can be increased from 10.36 mA/cm2 to 12.78 mA/cm2, and a power conversion efficiency of 7.42 % can be obtained. To further understand the mechanism of the increased short-circuit current, thought the PL measurement, we can be clearly seen that the addition of PC71BM can effectively quench the fluorescence emitted by PBDB-T, indicating that PC71BM can help charge transfer. In addition, from AFM, the addition of PC71BM can reduce the surface roughness and form a smoother surface. From TEM, we observed a fibrous structure is produced without adding PC71BM. After adding PC71BM, the uniformity is getting better. When excessive addition, the fibrous structure disappeared, and PC71BM agglomerated to form a spherical structure, which can impede the transfer of charge. From the above results, the addition of PC71BM can increase the short-circuit current and increase the photoelectric conversion efficiency. Next, we used ITIC instead of PC71BM to observe the photoelectric properties. After measurement, we found that adding ITIC can result in 6.87% power conversion efficiency, mainly due to the short circuit current rising from 10.36 mA/cm2 to 11.45 mA/cm2. Though the PL masurement, ITIC can also absorb the fluorescence emitted by PBDB-T. From this result, it is known that this addition method is extensive.