Publication: Bodipy türevli̇ çapraz bağlı elektroakti̇f ince filmler ve fotodesenleme çalışmaları
Abstract
Fotodesenleme tekniği, mikroelektronik, biyomedikal mühendisliği, malzeme bilimi, OLED, sensör, optoelektronik cihaz uygulamalarında kullanılan yaygın bir metottur. Fotodesenleme işlemi, ışık ile indüklenen madde, desenli bir maske ve uygun dalga boyunda bir ışık kullanılarak gerçekleştirilir. Fotodesenleme süreciyle santimetre boyutundan nanometre boyutuna kadar yüzeyde desenleme işlemi gerçekleştirilebilmektedir. BODIPY (4,4-difloro-4-bora-3a,4a-diaza-s-indasen) boyaları, küçük Stokes kaymaları, dar absorpsiyon bantları, keskin emisyonları, yüksek floresans kuantum verimleri ve foto-kararlılıkları sebebiyle ilgi çekici maddelerdir. BODIPY’lerin bu özellikleri, yüksek şiddette ışık emisyonu göstermelerine ve elektron transfer ajanları olarak optoelektronik uygulamalarda kullanılabilmelerine olanak sağlamaktadır. BODIPY, aldehit ve pirolün türevlendirilmesiyle oldukça geniş bir sübstitüent yelpazesine sahiptir. BODIPY içeren konjuge yapıdaki moleküllerin yanında, tekrarlanan birimde BODIPY iskelet yapısını içeren polimerler de literatürde yer almaktadır. Düşük bant boşluklu konjuge monomer ve polimerler geliştirmenin ana yollarından biri donör-akseptör yaklaşımıdır. Bu yaklaşım, elektronik cihaz uygulamaları ve özellikle elektrokromikler ve fotovoltaikler için konjuge moleküllerin elektronik yapısının kontrol edilmesinde son derece önemlidir. BODIPY bileşikleri modifiye edilmediğinde 500 nm’den daha uzun dalga boylarında absorplama ve emisyon yaparlar ve bu durum BODIPY bileşiklerinin organik yarı iletken olarak kullanılabilirliklerini kuvvetlendirir. BODIPY’lerin optik bant boşluklarını azaltmak, böylece emisyonu kırmızıya doğru kaydırmak için kullanılan en yaygın yöntemlerden birisi BODIPY üzerine donör gruplar ilave edilmesidir. Tiyol-en klik reaksiyonu Sharpless tarafından tanımlanmıştır ve oldukça verimli ve kolay bir reaksiyon türüdür. Tiyol-en klik reaksiyonu, alken ve tiyol grupları varlığında ışıkla serbest radikal oluşturarak veya Michael katılması şeklinde gerçekleştirilebilir. Bu tez çalışmasında stiren grubu içeren dört farklı BODIPY türevleri sentezlenmiş ve tiyol bazlı bağlayıcı kullanılarak tiyol-en klik reaksiyonuyla çapraz bağlanmıştır. İnce film yüzeyinde elde edilen çapraz bağlı polimerlerin karakterizasyonları yapılmış, ardından fotofiziksel, elektrokimyasal ve yüzey kimyası incelenmiştir.
Photopatterning is a common technique used in microelectronics, biomedical engineering, materials science, OLEDs, sensors, and optoelectronic device applications. The photopatterning process is performed using an inducible substance, a patterned mask, and light of an appropriate wavelength. The photopatterning process can be used to pattern surfaces from centimeters to nanometers in size. BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes are interesting substances due to their small Stokes shifts, narrow absorption bands, sharp emissions, high fluorescence quantum yields, and photostability. These properties enable BODIPYs to exhibit high-intensity light emission and be used as electron transfer agents in optoelectronic applications. BODIPY has a wide range of substituents due to the derivatization of aldehyde and pyrrole. In addition to conjugated molecules containing BODIPY, polymers containing the BODIPY skeleton structure in the repeating unit are also found in the literature. One of the main ways to develop low bandgap conjugated monomers and polymers is the donor-acceptor approach. This approach is extremely important in controlling the electronic structure of conjugated molecules for electronic device applications, especially electrochromic and photovoltaics. BODIPY compounds absorb and emit at wavelengths longer than 500 nm when not modified, which strengthens the usability of BODIPY compounds as organic semiconductors. One of the most common methods used to reduce the optical bandgap of BODIPYs and thus shift the emission to the red is to add donor groups to BODIPY. The thiol-ene click reaction was defined by Sharpless and is a type of reaction that is quite efficient and easy. The thiol-ene click reaction can be performed either by generating free radicals with light in the presence of alkenes and thiol groups or by Michael addition. In this thesis study, four different BODIPY derivatives containing the styrene group were synthesized and cross-linked by the thiol-ene click reaction using a thiol-based binder. The characterizations of the cross-linked polymers obtained on the thin film surface were performed, and then the photophysical, electrochemical, and surface chemistry were investigated.
Photopatterning is a common technique used in microelectronics, biomedical engineering, materials science, OLEDs, sensors, and optoelectronic device applications. The photopatterning process is performed using an inducible substance, a patterned mask, and light of an appropriate wavelength. The photopatterning process can be used to pattern surfaces from centimeters to nanometers in size. BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes are interesting substances due to their small Stokes shifts, narrow absorption bands, sharp emissions, high fluorescence quantum yields, and photostability. These properties enable BODIPYs to exhibit high-intensity light emission and be used as electron transfer agents in optoelectronic applications. BODIPY has a wide range of substituents due to the derivatization of aldehyde and pyrrole. In addition to conjugated molecules containing BODIPY, polymers containing the BODIPY skeleton structure in the repeating unit are also found in the literature. One of the main ways to develop low bandgap conjugated monomers and polymers is the donor-acceptor approach. This approach is extremely important in controlling the electronic structure of conjugated molecules for electronic device applications, especially electrochromic and photovoltaics. BODIPY compounds absorb and emit at wavelengths longer than 500 nm when not modified, which strengthens the usability of BODIPY compounds as organic semiconductors. One of the most common methods used to reduce the optical bandgap of BODIPYs and thus shift the emission to the red is to add donor groups to BODIPY. The thiol-ene click reaction was defined by Sharpless and is a type of reaction that is quite efficient and easy. The thiol-ene click reaction can be performed either by generating free radicals with light in the presence of alkenes and thiol groups or by Michael addition. In this thesis study, four different BODIPY derivatives containing the styrene group were synthesized and cross-linked by the thiol-ene click reaction using a thiol-based binder. The characterizations of the cross-linked polymers obtained on the thin film surface were performed, and then the photophysical, electrochemical, and surface chemistry were investigated.