Effects of illumination on the electrical characteristics in organic thin-film transistors based on dinaphtho [2,3-b:2',3'-f] thieno[3,2-b] thiophene (DNTT): Experiment and modeling

The electrical properties of dinaphtho [2,3-b:2 ',3 '-f]thieno[3,2-b]thiophene (DNTT) based organic thin film transistors (DNTT-TFTs) were investigated in detail under dark and various light illumination conditions with different channel lengths. We have exploited the experimental curves current-voltage of our TFT to extract electrical parameters such us mobility, threshold voltage, sub-threshold voltage and trapped density in dark and under illumination. By using an analytical model, we are able to reproduce very accurately the output and transfer characteristics with a joint analysis of the L = 100 mu m and L = 500 mu m electrical characteristics, the dependence of the contact resistance (R-c) upon the illumination conditions has been extracted. The used model gives a good agreement between the measured current-voltage characteristics of the DNTT-TFTs and those modeled in all measurement conditions (in dark and under illumination).