In this paper, we have proposed to apply a combinatorial approach to investigate the Schottky diode based on electrochemically polymerized conjugated polymer. The concept of combinatorial approach was emerged in the biochemical field and lately used in the materials science to screen a number of experimental conditions efficiently. Some tips for designing the polymerization bath suitable for our purpose, such as the way to suppress the interference of polymerization currents, have been described. In the case of Schottky diodes based on poly (3-methylthiophene), the system chosen to test our idea, the effects of polymer thickness and the supporting salt on the device characteristics have been surveyed clearly and rapidly. The map or library of the relationship between the polymerization condition and device characteristic may be useful to tune the device characteristics as desired. Our preliminary result has shown that the combinatorial approach proposed here can be a powerful tool to investigate the conjugated polymer devices by electrochemical polymerization such as electrochromic devices.

A device structure for polymer Schottky diode, which has the glass chimney as a dopant reservoir enabling the reduction of series resistance without cathode corrosion, has been proposed. Doping with the acetonitrile solution of FeCl3 in the device resulted in the increase in the forward-bias current by one order of magnitude without notable increase in reverse-bias current, suggesting that the doping reduced the series resistance. It is found that the penetration speed depends on the solvents. Short time doping with the nitromethane solution of FeCl3 resulted in the increase by three orders of magnitude. However, doping for a long period yielded the considerable increase in the reverse-bias current due to the complete penetration of dopatn solution. When the upper opening of glass chimney of device is left opened and the sample after doping stored in air, the forward-bias current of the device reduced rapidly due to the undoping and/or degradation of polymer. It is possible to protect the degradation of device characteristics after doping, by sealing the chimney and storing the device in vacuum.

As new applications of THz waves emerge, new active and passive components need to be developed. The efficiency of wave guiding systems can be significantly increased with the use of MEMS approaches as well as with the development of new planar antenna concepts with high bunching properties. Generation of sufficient THz power relies on new active devices like Heterostructure Barrier Varactors and cascaded quantum structures, but also in the optimisation of new generation concepts. One of these is photomixing in non-linear materials with very short carrier lifetimes, like low-temperature-grown GaAs.