Solution Processed Organic Transistors on Paper Substrate for Sustainable Electronics
Gargi Konwar, Vivek Raghuwanshi, Pulkit Saxena, Sachin Rahi, Somnath Bhattacharjee, Shree Prakash Tiwari
Abstract
Ecofriendly solution processed organic transistors were demonstrated on a biodegradable paper substrate for −5-V operation. Blend of solution processed organic semiconductor TIPS-pentacene and polystyr- ene (PS) polymer was utilized to form the active layer, along with a natural protein, i.e., gelatin as a primary gate dielectric, both of which offer eco-friendliness from proc- ess and material aspects. Fabricated organic transistors showed excellent transistor behavior for p-channel opera- tion with a maximum process transconductance value of 15 nF/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> leading to the mobility of 2.3 cm2/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> obtained from capacitance density derived at 1 kHz. The average threshold voltage of −0.7 V suitable for low-voltage opera- tion was achieved along with decent ON/OFF current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 10^{{4}}$ </tex-math></inline-formula> . High electrical stability was demonstrated through repeatability of transfer characteristics and bias-stress measurements. Excellent environmental stability in normal ambient was observed up to seven weeks. These devices showed circuit applicability with decent switching in resis- tive load inverters and good sensitivity to ultraviolet (UV) light, making them a suitable candidate for exploration for multifunctional and disposable application.