| 초록 |
pTTDPP–BT polymers consisting of electron−rich thienothiophene (TT), electron−deficient diketopyrrolopyrrole (DPP), and benzothiadiazole (BT) units were synthesized and used to fabricate phototransistors. The photo−responsive properties of the pTTDPP–BT phototransistors were investigated as a function of the annealing temperature. As−spun pTTDPP–BT phototransistors exhibited low hole and electron mobilities of 0.007 and 0.005 cm2V-1s-1, respectively, which resulted in low photocurrent detection. Thermal annealing of the polymer film resulted in a significant increase in the carrier mobilities (hole and electron mobilities of 0.066 and 0.115 cm2V-1s-1, respectively, for 200 °C annealing) and thus significantly improved photo−responsive properties. The 200 °C-annealed phototransistors showed a broad spectral photo−response in the infrared, visible, and ultraviolet regions, a high photocurrent/dark-current ratio of 150, and a fast switching speed of less than 100 ms. |
