An Easily Accessible Donor鈭捪€-Acceptor-Conjugated Small Molecule from a 4,8-Dialkoxybenzo[1,2-b:4,5-b鈥瞉dithiophene Unit for Efficient Solution-Processed Organic Solar Cells
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- 作者：Pranabesh Dutta ; Jeongseok Kim ; Seung Hun Eom ; Woo-Hyung Lee ; In Nam Kang ; Soo-Hyoung Lee
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：December 26, 2012
- 年：2012
- 卷：4
- 期：12
- 页码：6669-6675
- 全文大小：467K
- 年卷期：v.4,no.12(December 26, 2012)
- ISSN：1944-8252
文摘
A new donor鈥揳cceptor-conjugated organic small molecule, BDT(TBT)2, comprised of benzo[1,2-b:4,5-b鈥瞉dithiophene and 2,1,3-benzothiadiazole units was designed and synthesized. The small molecule BDT(TBT)2 in its thin film showed an absorption band in the range of 300鈥?00 nm with an absorption edge at 650 nm and an optical band gap of 1.90 eV. As estimated from the cyclic voltammetry measurements, the HOMO and LUMO energy levels of BDT(TBT)2 were 鈭?.44 and 鈭?.37 eV, respectively. The spin-coated thin film of BDT(TBT)2 exhibited p-channel output characteristics with a hole mobility of 2.7 脳 10鈥?. BDT(TBT)2, when explored as an electron-donor material in solution-processed bulk-heterojunction organic solar cells in conjunction with a PC71BM acceptor with an active layer thickness of 50鈥?5 nm, generated a power conversion efficiency (PCE) of 1.18%. A more impressive PCE of 2.9% with a short-circuit current density (Jsc) of 7.94 mA cm鈥? and an open-circuit voltage (Voc) of 0.89 V was achieved when the active layer of the cell was annealed at higher temperature (180 掳C).