Wider manifestation of low-cost syringe-based printer for realizing printed organic electronic devices and supercapacitors

Abstract

Additive manufacturing has emerged as an inexorable aspect in the advancement of organic electronics and energy storage technologies, especially considering the advantages of printing techniques and functional materials. Printing technology offers benefits like minimal material wastage due to its capability of pattern printing and a smooth transition from laboratory to mass production. In this context, an in-house developed, custom-built, cost-effective syringe-based printer is introduced. By controlling the extrusion amount and feed rate, thin films are optimized to achieve the desired thickness and morphology, which are crucial for high-performance, low-voltage operating Organic Field-Effect Transistors (OFETs) and Organic Solar Cells (OSCs). The printed OSC, with a device architecture of ITO/ZnO/PTB7-Th:PC₇₁BM/MoO_x/Ag, has achieved a Power Conversion Efficiency (PCE) of up to 6.65%, comparable to spin-coated devices of the same architecture. Additionally, the OFETs produced using this method have shown comparable charge carrier mobility of approximately 7.83 × 10⁻² cm² V⁻¹ s⁻¹ and consistently higher I_ON/I_OFF ratios than the spin coated devices. Printed devices consume less material for their fabrication than spin coated devices due to selective pattern printing, and the printer can handle film thicknesses ranging from a few nanometers to micrometers. To further demonstrate the micron-level capability of the printer, a fully printed, eco-friendly, solid-state flexible supercapacitor was successfully fabricated. The supercapacitor exhibited impressive electrochemical performance, achieving a specific capacitance of 58 mF cm⁻² at a current density of 3.00 mA cm⁻² and an energy density of 8.00 μWh cm⁻². These results indicate that the low-cost syringe-based printer is a viable and superior technological alternative in the realm of flexible and printed electronics.