Organic thin film transistors
View Patent ↗An organic thin film transistor has a gate dielectric layer which is formed from a block copolymer. The block copolymer comprises a polar block and a nonpolar block. The resulting dielectric layer has good adhesion to the gate electrode and good compatibility with the semiconducting layer.
1. An organic thin film transistor comprising a substrate, a semiconductor layer, and a gate dielectric layer, wherein the gate dielectric layer comprises a block copolymer, wherein the block copolymer comprises a polar block and a nonpolar block, the polar block is bisphenol-A polycarbonate, and the nonpolar block is polydimethylsilane.
2. The transistor of claim 1 , wherein the gate dielectric layer is in the form of a first layer comprising a majority of the polar block of the block copolymer and a second layer comprising a majority of the nonpolar block of the block copolymer, wherein the second layer is closer to the semiconductor layer than the first layer.
3. The transistor of claim 2 , wherein the first layer contains from about 60% to 100% by weight of the polar block, based on the total weight of the first layer.
4. The transistor of claim 2 , wherein the second layer contains from about 60% to 100% by weight of the nonpolar block, based on the total weight of in the second layer.
5. The transistor of claim 1 , wherein the gate dielectric layer is phase-separated into (i) a continuous phase comprising a majority of the nonpolar block of the block copolymer; and (ii) a discontinuous phase comprising a majority of the polar block of the block copolymer.
6. The transistor of claim 1 , wherein the block copolymer is crosslinked.
7. The transistor of claim 1 , wherein the gate dielectric layer further comprises inorganic nanoparticles, wherein a majority of the nanoparticles is dispersed in a phase formed from the polar block.
8. The transistor of claim 7 , wherein the inorganic nanoparticles are formed in-situ in the presence of the block copolymer.
9. The transistor of claim 1 , wherein the semiconducting layer comprises a polythiophene.
10. The transistor of claim 9 , wherein the polythiophene has one of the three following structures:
where R and R′ are independently selected from hydrogen, halogen, alkyl, alkoxyalkyl, siloxyalkyl, and perfluoroalkyl; M is a divalent linkage; and n is the degree of polymerization.
11. An organic thin film transistor comprising a substrate, a semiconductor layer, and a gate dielectric layer, wherein the gate dielectric layer consists of a block copolymer, wherein the block copolymer has a polar block and a nonpolar block, the polar block is bisphenol-A polycarbonate, and the nonpolar block is polydimethylsilane.
12. An organic thin film transistor comprising a substrate, a semiconductor layer, and a gate dielectric layer, wherein the gate dielectric layer consists of inorganic nanoparticles and a block copolymer, wherein the block copolymer has a polar block and a nonpolar block, the polar block is bisphenol-A polycarbonate, and the nonpolar block is polydimethylsilane.