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 µm and L = 500 µm electrical characteristics, the dependence of the contact resistance (Rc) 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).