PEDOT:PSS kapı elektrodlu alan-etkili transistörlerde kapı yalıtkanının transistör parametreleri üzerine etkileri
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Dosyalar
Tarih
2018
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Organik alan-etkili transistörler (OFET'ler) esnek yapıları ve düşük üretim maliyetleri nedeniyle bir elektronik bileşen olarak elektronik devrelerde kullanılmak üzere son dönemde yoğun olarak çalışılmaktadır. OFET'lerde organik yarıiletkenin yanında kapı yalıtkanı da yarıiletken-dielektrik arayüzeyindeki yük taşınımını etkileyen bir etmen olması dolayısıyla çok önemli bir bileşendir. Uygun kapı yalıtkanlarının OFET'e eklenmesiyle transistörlerin performansı ciddi oranlarda yükselebilmektedir. Bu bağlamda, OFET'lerin elektronik parametre değerlerini iyileştirmek için üniversitemiz kimyacıları tarafından sentezlenen ve literatürde çok kullanılan poli(metil-metakıralat) (PMMA)'ya göre mekanik olarak esneklik avantajına sahip organik polimer poli(metilakrilat) (PMA) ince-film halinde ve polimerin jel haline getirilmesi vasıtasıyla jel halinde üretilen transistörlerde kapı yalıtkanı olarak kullanılmıştır. Ayrıca PMA polimerinin orjinal olarak sentezlenen dört adet kopolimeri de (P18, P28, P29 ve P30) polimerizasyon sürecinde metil akrilata (MA) belli oranlarda soya yağı eklenmesiyle elde edilmişdir. İnce-film halinde kaplanan PMA, PMMA'ya göre daha yüksek mobilite ve daha düşük eşik gerilimi (VTH) gibi bir özellik sergilese de akım açma-kapama oranı (ION?IOFF) ve eşikaltı salınımı (SS) gibi parametrelerde, yüksek kapı sızıntı akımından (IOFF) dolayı düşük performans göstermiştir. IOFF değerini ve transistörün çalışma voltajını düşürmek adına PMA ve yukarıda bahsedilen kopolimerleri jel haline getirilmiş ve OFET'lerde kapı yalıtkanı olarak kullanılmıştır. Sonuç olarak bu şekilde üretilen transistörlerle hem çalışma voltajlarının düşürülebildiği hem de kopolimerlerdeki polimerleşme sürecinde soya yağı MA oranının arttırılmasıyla jel dielektriklerin bağıl dielektrik katsayılarının düşürülebildiği ve bu sayede OFET'in en önemli parametrelerinden biri olan mobilitenin yükseltilebildiği görülmüştür. Dahası, kapı yalıtkanlarının jel haline getirilip kullanılmasıyla IOFF akımının da azaltılabileceği ispatlanmıştır. Bunların yanında şunu da belirtmek gerekir ki; poli(3,4-etilendioksitiyofen) polistren sülfonat (PEDOT: PSS) organik iletken formulasyonunun kapı elektrodu olarak tasarımlarda kullanılmasıyla cihazların performansının dahada yükselebildiği tespit edilmiştir. Son olarak, yukarıda bahsedilen kapı yalıtkanları ve teknikleri kullanılarak basit ve ucuz yöntemlerle üretilen OFET'lerin elektronik osilatör ve evirici gibi elektronik devrelerinde devre elemanı olarak kullanılma potansiyelinin olduğu söylenebilir.
Organic field-effect transistors (OFETs), recently have been studied intensively for their usage as an electronic component in electronic circuits because of their flexibility and low production costs. In OFETs, besides the organic semiconductor, gate insulators are also important components since they have a high impact on the charge transport in the semiconductor-dielectric interface. Performance of the transistors can be improved significantly via adding compatible gate insulators in OFETs. In this regard, in order to enhance the parameter values of the OFETs, poly(methyl-acrylate (PMA) which was synthesized by chemist of our university and more flexible compared to the heavily used poly(methyl-methacrylate) (PMMA) in the literature was used as gate insulators in OFETs both as thin-film and gel states. Copolymers of the PMA (P18, P28, P29, and P30) were originally synthesized and obtained by adding particular amount of soybean oil to the methyl acrylate (MA) in the polymerization process. Even though coated thin-film PMA was proven to have a higher mobility and lower threshold voltage (VTH) compared to the coated PMMA thin-film, on-to-off current ratio (ION?IOFF) and subthreshold swing (SS) parameters were exhibited a lower performance since the higher gate leakage current (IOFF). Therefore, PMA and above-mentioned copolymers of the PMA were transformed into the gel state and used as gate insulators in order to decrease the IOFF and operating voltage of the devices. Consequently, it was demonstrated that operating voltage of the devices can be decreased in this way. Furthermore, relative dielectric constant of the gel dielectric can also be decreased by increasing the soybean oil to MA weight ratio in the polimerization process and it was proven that this led the enhancement of mobility. Moreover, it was shown that transforming the gate insulators into gel state lowers the value of IOFF. Besides all of that, it was shown that using the poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) formulation as a gate electrode in designs enhanced the performance of the devices further. Finally, it can be said that by using above mentioned gate insulators and simple techniques, OFETs can be fabricated with a low budget and then they can be potentially used in electronic oscillator and inverter circuits.
Organic field-effect transistors (OFETs), recently have been studied intensively for their usage as an electronic component in electronic circuits because of their flexibility and low production costs. In OFETs, besides the organic semiconductor, gate insulators are also important components since they have a high impact on the charge transport in the semiconductor-dielectric interface. Performance of the transistors can be improved significantly via adding compatible gate insulators in OFETs. In this regard, in order to enhance the parameter values of the OFETs, poly(methyl-acrylate (PMA) which was synthesized by chemist of our university and more flexible compared to the heavily used poly(methyl-methacrylate) (PMMA) in the literature was used as gate insulators in OFETs both as thin-film and gel states. Copolymers of the PMA (P18, P28, P29, and P30) were originally synthesized and obtained by adding particular amount of soybean oil to the methyl acrylate (MA) in the polymerization process. Even though coated thin-film PMA was proven to have a higher mobility and lower threshold voltage (VTH) compared to the coated PMMA thin-film, on-to-off current ratio (ION?IOFF) and subthreshold swing (SS) parameters were exhibited a lower performance since the higher gate leakage current (IOFF). Therefore, PMA and above-mentioned copolymers of the PMA were transformed into the gel state and used as gate insulators in order to decrease the IOFF and operating voltage of the devices. Consequently, it was demonstrated that operating voltage of the devices can be decreased in this way. Furthermore, relative dielectric constant of the gel dielectric can also be decreased by increasing the soybean oil to MA weight ratio in the polimerization process and it was proven that this led the enhancement of mobility. Moreover, it was shown that transforming the gate insulators into gel state lowers the value of IOFF. Besides all of that, it was shown that using the poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) formulation as a gate electrode in designs enhanced the performance of the devices further. Finally, it can be said that by using above mentioned gate insulators and simple techniques, OFETs can be fabricated with a low budget and then they can be potentially used in electronic oscillator and inverter circuits.
Açıklama
YÖK Tez No: 543059
Anahtar Kelimeler
Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering
