Conduction mechanisms in poly(3-hexylthiophene) thin-film sandwiched structures

Current density-voltage ( J-V) characteristics of regioregular poly( 3-hexylthiophene) ( P3HT) thin-film sandwiched structures are studied and analyzed in this paper. Various material and trap parameters are estimated using the space-charge-limited conduction model with exponential trap distribution. Temperature-dependent J-V characteristics are examined to justify the bulk-limited transport in the material and trap density ( H-beta) and characteristic constant ( Et) are determined. The model is modified using field-dependent trap occupancy ( FDTO) and compared. Both the models, with and without FDTO, fit the J-V curves at different temperatures. Though the model with FDTO fits the J-V curve slightly better at high voltages when compared to the model without FDTO, it cannot be established with certainty.