Large-scale complementary integrated circuits based on organic transistors

Thin-film transistors based on molecular and polymeric organic materials ha ve been proposed for a number of applications, such as displays(1-3) and ra dio-frequency identification tags(4-6). The main factors motivating investi gations of organic transistors are their lower cost and simpler packaging, relative to conventional inorganic electronics, and their compatibility wit h flexible substrates(7,8). In most digital circuitry, minimal power dissip ation and stability of performance against transistor parameter variations are crucial. In silicon-based microelectronics, these are achieved through the use of complementary logic-which incorporates both p- and n-type transi stors-and it is therefore reasonable to suppose that adoption of such an ap proach with organic semiconductors will similarly result in reduced power d issipation, improved noise margins and greater operational stability. Compl ementary inverters and ring oscillators have already been reported(9,10). H ere we show that such an approach can realize much larger scales of integra tion (in the present case, up to 864 transistors per circuit) and operation speeds of similar to 1 kHz in clocked sequential complementary circuits.