Development of Organic FET/LD Using Self-Organized Low-Dimensional Crystals

在这项发展有机激光二极管(OLD)的研究中，我们首次发现无镜激光作用于基于受激共振拉曼散射(SRRS)的噻吩苯低聚物(TPCO)的低维晶体。这种光放大效应归因于具有较大振荡强度的单轴取向跃迁偶极子中的相干分子振动。由于TPCO晶体的SRRS现象具有波长可调谐范围宽、ASE噪声低等优点，可以应用于有机光放大器和OLD的开发。为了将TPCO晶体优越的光放大能力应用于OLD的开发，我们接下来利用P/N异质结结构的有机场效应晶体管(OFET)研究了其载流子注入和输运特性。用N型C60和P型TPCO共蒸发或叠层薄膜制作的场效应管器件表现出双极注入EL-…此外，我们还通过沉积Au源电极和Al：Li漏电极制备了具有TPCO薄膜的顶接触场效应管器件。由于不同功函数金属的非对称电极结构，这些器件在负栅电压作用下表现出电流注入光发射。显微镜观察表明，光发射只发生在漏电极的边缘。这表明在TPCO沟道中积累的空穴与漏-电极界面处的电子复合。因此，由于没有实现电子注入到TPCO薄膜中，发射强度仍然较低。为了进一步发展OLD，我们应该继续寻找具有与TPCO空穴迁移率相媲美的高电子迁移率的新的N型半导体分子。此外，我们必须通过控制ET结构的P/N结来提高沟道层中的双极载流子积累和复合效率。较少

In this study towards development of organic laser diodes (OLD), we first found that mirror-less laser actions from low-dimensional crystals of thiophene/phenylene co-oligomers (TPCO) based on stimulated resonant Raman scattering (SRRS). This light amplification effects was attributed to coherent molecular vibrations in the uniaxially oriented transition dipoles with large oscillation strength. Since the SRRS phenomena of the TPCO crystals can applicable to development of organic optical amplifiers and OLDs because of their advantages such as wide wavelength tunability with low ASE noise.In order to apply the superior light-amplification abilities of the TPCO crystals to development of OLDs, we next investigated their carrier injection and transport properties by using organic field-effect transistors (OFET) with P/N heterojunction structures. The OFET devices fabricated with co-evaporated or laminated thin films of N-type C_<60> and P-type TPCO exhibited ambipolar injection of both el … More ectrons and holes.Furthermore, we fabricated top-contact OFET devices with TPCO thin films by depositing Au source and Al:Li drain electrodes. Due to their asymmetric electrode structure with different work-function metals, those devices showed current-injected light emission under application of negative gate voltages. Microscopic observations revealed that the light emission occurred only at the edge of the drain electrode. It suggests that the holes accumulated in the TPCO channel recombine with the electrons at the drain-electrode interface. Therefore, the emission intensity is still low because the electron injection into the TPCO film is not achieved.For future progress towards development of OLDs, we should continue to find new N-type semiconducting molecules which posses high electron mobilities comparable to the hole mobility of TPCO. Furthermore, we have to improve ambipolar carrier accumulation and recombination efficiencies in the channel layer by controlling the P/N junction OFET structures. Less