Electronic devices support our highly developed society, and silicon semiconductors are essential components of these devices. However, problems in their use include the limitations of processing technology and functionality, which still falls far short of the brain. The brains of animals and humans are built around organic compounds which possess higher capability and functionality than current Si semiconductors. Extensive research has been conducted on organic compounds for their use as high-functionality and high-capability semiconductors. The research covers areas that could lead to the significant expansion in the application of organic compounds in optoelectronic devices. Liquid crystals or organic electroluminescence (EL) are already practical applications of these compounds. The related reagents are listed according to the research area: organic EL, conducting polymers, charge transfer complexes and photochromic compounds, etc.