Nakamura Tomoya, Ishikura Yasuhisa, Arakawa Noriko, Hori Megumi, Satou Motoi, Endo Masaru, Masui Hisashi, Fuse Shinichiro, Takahashi Takashi, Murata Yasujiro, Murdey Richard, Wakamiya Atsushi
Institute for Chemical Research, Kyoto University Gokasho Uji Kyoto 611-0011 Japan
Department of Pharmaceutical Sciences, Yokohama University of Pharmacy 601, Matano-cho, Totsuka-ku Yokohama 245-0066 Japan.
RSC Adv. 2019 Mar 1;9(13):7107-7114. doi: 10.1039/c9ra00229d.
Two p-type semiconducting donor-acceptor polymers were designed and synthesized for use in organic solar cells. The polymers combine a benzodithiophene (BDT) donor and a thiazole-fused benzothiadiazole (TzBT) acceptor. Two TzBT acceptor units are compared, one with an alkylthio group (P1) and the other with a more strongly electron-withdrawing alkylsulfonyl group (P2) at the fused thiazole ring. The strongly electron-accepting nature of the TzBT unit lowers the lowest unoccupied molecular orbital (LUMO) energy of P1 and P2 relative to that of the BT analog (PBDT-BT), without altering the energy of the highest occupied molecular orbital (HOMO). Despite the smaller optical band gaps, bulk heterojunction organic solar cells fabricated using these polymers in a PCBM blend showed high open-circuit voltages. The power conversion efficiency (PCE) of the P1-based device reached 6.13%. Though efficiency of the P2-based device was lower, photoelectric conversion extended into the near-IR region up to 950 nm.
设计并合成了两种用于有机太阳能电池的p型半导体供体-受体聚合物。这些聚合物将苯并二噻吩（BDT）供体和噻唑稠合苯并噻二唑（TzBT）受体结合在一起。比较了两个TzBT受体单元，一个在稠合噻唑环上带有烷硫基（P1），另一个带有吸电子能力更强的烷基磺酰基（P2）。TzBT单元的强吸电子性质相对于BT类似物（PBDT-BT）降低了P1和P2的最低未占分子轨道（LUMO）能量，而不改变最高占据分子轨道（HOMO）的能量。尽管光学带隙较小，但在PCBM共混物中使用这些聚合物制备的本体异质结有机太阳能电池显示出高开路电压。基于P1的器件的功率转换效率（PCE）达到6.13%。尽管基于P2的器件效率较低，但其光电转换扩展到了高达950 nm的近红外区域。
