PENTACENE ORGANIC THIN-FILM TRANSISTORS - MOLECULAR ORDERING AND MOBILITY

Pentacene-based organic thin-film transistors (TFT's) with field-effec t mobility as large as 0.7 cm(2)/V . s and on/off current ratio larger than 10(8) have been fabricated. Pentacene films deposited by evapora tion at elevated temperature at low-to-moderate deposition rates have a high degree of molecular ordering with micrometer-sized and larger d endritic grains. Such films yield TFT's with large mobility. Films dep osited at low temperature or by flash evaporation have small grains an d poor molecular ordering and yield TFT's with low mobility.