Synthesis, photophysical and photovoltaic properties of 11-fluorodibenzo[a,c]phenazine bearing donor–acceptor type conjugated polymers


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye

Tezin Onay Tarihi: 2016

Öğrenci: ECE AKTAŞ

Danışman: LEVENT KAMİL TOPPARE

Özet:

In this study, dibenzo[a,c]phenazine moiety was modified with fluorine atom to decrease the HOMO level of acceptor unit. Benzodithiophene derivative and dibenzosilole derivative were used as donor unit in the polymer backbone. In addition, 3-hexyltihophene was used as the π-bridge molecule with their donor character in polymer backbone. Also, 3,4-ethylenedioxythiophene was used to obtain new monomer to compare oxidation potential with 3-hexylthiophene based monomer. In this manner, two new conjugated monomers (PTFBPz and PEFBPz) and two new conjugated polymers (PBDT-FBPz and PBDT-TFBPz) were synthesized via Stille cross-coupling. In addition, the new conjugated polymer (PSi-TFBPz) was synthesized via Suzuki cross-coupling reactions. The electrochromic studies of all homopolymers and copolymers were performed and HOMO-LUMO energy levels of them were calculated. The absorption properties of polymers were investigated in solution and thin film. The photovoltaic studies of three polymers were performed. All photovoltaic devices were constructed with the conventional device structure (ITO/PEDOT:PSS/polymer:PCBM71/LiF/Al). In addition, the photovoltaic device fabrication and current-voltage characteristics of these devices were studied in an oxygen and moisture free glove box system. The power conversion efficiency (PCE) of conjugated polymers were measured under standard AM 1.5 Global illumination (100mW/cm2). The highest PCE values was found as 1.53% for PBDT-TFBPz, 1.12% for PBDT-FBPz and 0.58% for PSi-TFBPz.