Significant improvement of 2,9-DPh-DNTT organic thin-film transistors based on organic heterojunction buffer layer

High-mobility thin film transistors ofpara-sexiphenyl (p-6P)/2,9-diphenyl-dinaphtho[2,3-b:2',3'-f]-thieno[3,2-b] thiophene (2,9-DPh-DNTT) are demonstrated by employing copper hexadecafluorophthalocyanine (F16CuPc), cobalt (II) hexadecafluoro-phthalocyanine (F16CoPc) and molybdenum oxide (MoO3) as buffer layers. The highest field-effect mobility of 9.3 cm(2)/Vs is achieved by using the F16CoPc buffer layer, which is the highest reported mobility for polycrystalline 2,9-DPh-DNTT thin film transistors. The improvement of the device performance is due to reducing device contact resistance between metal electrodes and the organic semiconductor and improving the carrier injection. Based on the optimized results, we fabricated an OTFT array consisting of p- 6P/2,9-DPh-DNTT OTFTs with F16CoPc as the buffer layer by photolithography. A high mobility of 2.7 cm(2)/Vs and a low VT of -2.3 V are achieved which proved that 2,9-DPh-DNTT is an excellent organic semiconductor in the field such as a large-area display and sensor matrix, etc.

Automated summary

High-mobility thin film transistors of p-6P/2,9-DPh-DNTT were demonstrated using different buffer layers, with F16CoPc achieving the highest reported mobility. The optimized device performance was attributed to reduced contact resistance and improved carrier injection. An OTFT array with high mobility and low VT was fabricated, proving the potential of 2,9-DPh-DNTT in large-area displays and sensor arrays.