研究実績の概要 |
A novel method for single-crystal (SC) growth, called "indirect sublimation," was successfully used to grow crystals of 1,3,6,8-tetrakis(methylthio)pyrene (MT-pyrene), MS-pyrene, rubrene, DNTT, and pentacene. High-coverage uniform crystals were obtained for MT- and MS-pyrene, which were transferred to a substrate using a rubbing machine to create a high-coverage multi-SC (MSC) film for device applications. MSC film-based organic field-effect transistors (OFETs) using MT-pyrene showed good on/off characteristics and high carrier mobilities (>20 cm2 V-1 s-1), comparable to SC devices (30 cm2 V-1 s-1). The development of novel high-mobility organic semiconductor materials was also performed, with a focus on designing molecules with brickwork crystal structures similar to MT-pyrene. A simulation algorithm was developed to accurately predict known brickwork-related crystal structures (MT- and MS-pyrene), and it was applied to the design of 1,3,8,10-tetrakis(methylthio)peropyrene (MT-peropyrene), which was synthesized and evaluated. SC-OFETs made with MT-peropyrene showed very high mobilities (30 cm2 V-1 s-1). Further optimization of the indirect sublimation method for MT-peropyrene and other materials, as well as fabrication of OFET-based devices such as pseudo-CMOS inverters, is ongoing. Additionally, novel material screening and development are being performed.
|
今後の研究の推進方策 |
According to the research plan, in the second year the focus will be made on device applications of multi-single-crystal (MSC) films. Devices such as pseudo-CMOS inverters, logic gates, and RF-ID tags will be fabricated. The material choice, device architecture, and fabrication conditions will be optimized to achieve the best performance.
|
次年度使用額が生じた理由 |
The research proposed the development of a mechanical device for transferring single-crystal (SC) and introduction of a rubbing machine. Additionally, there was a need for costly expendable glassware to purify new organic semiconductor compounds through sublimation. These expenses were substantially cut by simplifying the transfer process, creating a homemade rubbing machine, and using less expensive glassware alternatives. The funds saved from this will be allocated to acquiring a two-channel source measuring unit to complement the existing four-channel system for enhanced device evaluation.
|