Field effect transistors and electrical device array, and methods for their preparation

Field effect transistor (100) of the present invention, a substrate (101) a gate electrode (102) formed on a gate insulating layer formed on the gate electrode (102) and (103), a gate insulating layer (103 ) and the source electrode formed on the (106, 109) and a drain electrode (104), in contact with the source electrode (106, 109) and a drain electrode (104), including carbon nanotubes formed therebetween n-type semiconductor layer and the (108), n-type semiconductor layer (108) n-type modifying polymer layer for fixing to the polarity conversion of p-type to n-type carbon nanotube is formed inherent on the (110) including. By performing the semiconductor protective layer (110) formed simultaneously with the semiconductor characteristic conversion of CNT, the procedure as simple. Thus, it is possible to provide a stable CNT-FET circuit even in the air.