One-Step Coating Processed Phototransistors Enabled by Phase Separation of Semiconductor and Dielectric Blend Film

Abstract

Fabrication of organic thin-film transistors (OTFTs) via high throughput solution process routes have attracted extensive attention. Herein, we report a simple one-step coating method for vertical phase separation of the poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly(methyl methacrylate) (PMMA) blends as semiconducting and dielectric layers in OTFTs. These OTFTs can be used as phototransistors for ultraviolet (UV) light detection, where the phototransistors exhibited great photosensitivity of 597.6 mA/W and detectivity of 4.25 × 1010 Jones under 1 mW/cm2 UV light intensity. Studies of the electrical properties in these phototransistors suggested that optimized P3HT contents in the blend film can facilitate the improvement of film morphology, and therefore form optimized vertical phase separation of the PMMA and P3HT. These results indicate that the simple one-step fabrication method creates possibilities for realizing high throughput phototransistors with great photosensitivity.

Straightforward Patterning of Functional Polymers by Sequential Nanosecond Pulsed Laser Irradiation

“…Wettability of the nanostructures surfaces was inspected by measuring the water contact angle and the obtained values are cited in Table 1 . Initial surface of P3HT is hydrophobic, in agreement with previous results reported in literature [ 64 ]. It has been previously reported that laser micro/nanostructuring and in particular LIPSS formation may provoke changes in the wettability of materials due to the morphological changes, to the chemical changes induced upon irradiation or to a combination of both factors.…”

A high-performance organic thin-film transistor with Parylene/PMMA bilayer insulation based on P3HT

“… 21 The use of low-k PMMA as an insulating layer has been conventionally reported for P3HT thin-film transistors. 22 , 23 , 24 However, when utilizing a sole layer of PMMA as the gate dielectric, OTFT currents are not suitably regulated due to the poor insulating properties of PMMA. 25 , 26 …”

Binder polymer influence on the electrical and UV response of organic field-effect transistors

“…In addition, it is known that binding polymers also have an effect on the device characteristics. [34][35][36][37] Here, it was found that the nature of the binding polymer influences the trap density of majority and minority charge carriers. The best OFET performance is found in the blend films exhibiting a lower level of traps, while the worst performance is encountered in the films with a higher level of majority charge carrier traps.…”