Great progress has been made in the field of ordinary semiconductor physics and associated technologies. For the time being, if we could use new materials such as organic semiconductors progress in electronics could be accelerated. Characteristics of organic semiconductors that are superior to others are: i) high photo-conductivity under irradiation along with low leakage current in the dark, ii) high sensitivity of the conductivity to various gases and to pressure. iii) possibility of using them in the amorphous state, iv) possibility of making devices of extremely small size, v) large...