Current distribution effects in organic sexithiophene field effect transistors investigated by lock-in thermography: Mobility evaluation issues

In this Letter, a lock-in thermography technique has been used to investigate the actual current distribution profile in the active channel region of organic field effect transistors. The high accuracy of the setup shows an evidence of nonuniformity in the current flow over the device area. The physical origin of this experimental occurrence is tentatively ascribed to a not uniform contact resistance distribution along the channel width or to inhomogeneities in the interface traps distribution. The subsequent implications on the carrier mobility evaluation are discussed too.

[1]  Michael S. Shur,et al.  An experimental study of contact effects in organic thin film transistors , 2006 .

[2]  T. Someya,et al.  A large-area wireless power-transmission sheet using printed organic transistors and plastic MEMS switches. , 2007, Nature materials.

[3]  M. Langenkamp,et al.  Lock-in contact thermography investigation of lateral electronic inhomogeneities in semiconductor devices , 1998 .

[4]  T. Someya,et al.  Integration of organic FETs with organic photodiodes for a large area, flexible, and lightweight sheet image scanners , 2005, IEEE Transactions on Electron Devices.

[5]  Hiroshi Kawaguchi,et al.  High mobility of pentacene field-effect transistors with polyimide gate dielectric layers , 2004 .

[6]  Fabio Biscarini,et al.  Spatially correlated charge transport in organic thin film transistors. , 2004, Physical review letters.

[7]  Otwin Breitenstein,et al.  Localization of weak heat sources in electronic devices using highly sensitive lock-in thermography , 2002 .

[8]  Marco Sampietro,et al.  Modeling of organic thin film transistors: Effect of contact resistances , 2007 .

[9]  Michael A. Haase,et al.  Pentacene-based radio-frequency identification circuitry , 2003 .

[10]  Gong Gu,et al.  Reversible memory effects and acceptor states in pentacene-based organic thin-film transistors , 2007 .

[11]  Henrique L. Gomes,et al.  Dynamics of Threshold Voltage Shifts in Organic and Amorphous Silicon Field‐Effect Transistors , 2007 .

[12]  R. Sarpeshkar,et al.  Large-scale complementary integrated circuits based on organic transistors , 2000, Nature.

[13]  F. J. Garcia Sanchez,et al.  New procedure for the extraction of basic a-Si:H TFT model parameters in the linear and saturation regions , 2001 .