Enhanced performance of benzothieno[3,2-b]thiophene (BTT)-based bottom-contact thin-film transistors.

Three new benzothieno[3,2-b]thiophene (BTT; 1) derivatives, which were end-functionalized with phenyl (BTT-P; 2), benzothiophenyl (BTT-BT; 3), and benzothieno[3,2-b]thiophenyl groups (BBTT; 4; dimer of 1), were synthesized and characterized in organic thin-film transistors (OTFTs). A new and improved synthetic method for BTTs was developed, which enabled the efficient realization of new BTT-based semiconductors. The crystal structure of BBTT was determined by single-crystal X-ray diffraction. Within this family, BBTT, which had the largest conjugation of the BTT derivatives in this study, exhibited the highest p-channel characteristic, with a carrier mobility as high as 0.22 cm(2) V(-1) s(-1) and a current on/off ratio of 1×10(7) , as well as good ambient stability for bottom-contact/bottom-gate OTFT devices. The device characteristics were correlated with the film morphologies and microstructures of the corresponding compounds.

Enhanced performance of solution-processed TESPE-ADT thin-film transistors.

A solution-processed anthradithiophene derivative, 5,11-bis(4-triethylsilylphenylethynyl)anthradithiophene (TESPE-ADT), is studied for use as the semiconducting material in thin-film transistors (TFTs). To enhance the electrical performance of the devices, two different kinds of solution processing (spin-coating and drop-casting) on various gate dielectrics as well as additional post-treatment are employed on thin films of TESPE-ADT, and p-channel OTFT transport with hole mobilities as high as ~0.12 cm(2) V(-1) s(-1) are achieved. The film morphologies and formed microstructures of the semiconductor films are characterized in terms of film processing conditions and are correlated with variations in device performance.

High-performance bottom-contact organic thin-film transistors based on benzo[d,d']thieno[3,2-b;4,5-b']dithiophenes (BTDTs) derivatives.

Three benzo[d,d']thieno[3,2-b;4,5-b']dithiophene (BTDT) derivatives, end-functionalized with benzothiophenyl (BT-BTDT; 2), benzothieno[3,2-b]thiophenyl (BTT-BTDT; 3), and benzo[d,d']thieno[3,2-b;4,5-b']dithiophenyl (BBTDT; 4), were prepared for bottom-contact/bottom-gate organic thin-film transistors (OTFTs). An improved one-pot [2 + 1 + 1] synthetic method of BTDT with improved synthetic yield was achieved, which enabled the efficient realization of new BTDT-based semiconductors. All of the BTDT compounds exhibited high performance p-channel characteristics with carrier mobilities as high as 0.34 cm(2)/(V s) and a current on/off ratio of 1 × 10(7), as well as enhanced ambient stability. The device characteristics have been correlated with the film morphologies and microstructures of the corresponding compounds.