Solution processed white light photodetector based N, N′-di (2-ethylhexyl)-3,4,9,10-perylene diimide thin film phototransistor

• A solution processed n-type organic phototransistor was fabricated.
• The geometry of device allows to be used double sided photo-sensor to detect light.
• The accumulation of charge carrier is effected strongly by illumination intensity.
• The current amplification was observed clearly under illumination without gate bias.

In this study, a solution-processed n-type photo-sensing organic thin film transistor was investigated using polymeric dielectric under different white light illuminations. N, N′-di (2-ethylhexyl)-3,4,9,10-perylene diimide and divinyl tetramethyl disiloxane-bis (benzo-cyclobutene) were used as a soluble active organic semiconductor and as a dielectric material, respectively. Stable amplification was observed in the visible region without gate bias by the device. The electrical characterization results showed that an n-type phototransistor with a saturated electron mobility of 0.6 × 10− 3 cm2/V·s and a threshold voltage of 1.8 V was obtained. The charge carrier density of the channel of the device exhibited photo-induced behaviors that strongly affected the electrical properties of the transistor. The photosensitivity and photoresponsivity values of the device were 63.82 and 24 mA/W, respectively. These findings indicate that perylene diimide is a promising material for use on organic based phototransistors.