* 일시/장소 : 5월 3일(월) 오후 1시~ , 자연과학동(E6) 이태규세미나실 2124호
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Title : Organic Bipolar Field-Effect Transistors
Abstract:
Polymer field-effect transistors (PFETs) show promise as the critical components for low-cost, flexible electronics with various applications including smart cards, electronic identification tags, and active matrix displays. These applications typically require complementary logic elements, which require both p-type and n-type transistors. In such a case, it is beneficial to utilize ‘bipolar’ FETs, which function both as p-channel and n-channel transistors and, therefore, reduce the complexity of device fabrication.
Organic materials typically show either significantly higher hole mobility or significantly higher electron mobility. Bulk heterojunction (BHJ) blend materials comprising both hole and electron transporting materials have therefore been used as one approach to realizing organic bipolar FETs. Among the parameters that can be optimized to achieve high performance bipolar FETs, the assembly of a bicontinuous network of holes and electrons is the most important factor in order to procure good hole and electron transport in BHJ blends.
To optimize the nanomorphology by good phase separation in BHJ films, thermal annealing method has applied for the BHJ material comprised of regioregular poly(3-hexylthiophene) (rr-P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PC61BM). As an alternative approach, a ‘chemical’ method for the tailoring of the BHJ nanomorphology in systems where thermal annealing is not effective was demonstrated. By incorporating a few volume percent of specific processing additives, the nanomorphology of BHJ materials was significantly improved, thereby enhancing the performance of BHJ solar cells and BiFETs.
나노과학기술대학원 책임교수 신중훈 배상.