Monolithic integration of display driver circuits and displays manufactured by screen printing

Abstract

Here, we report all-screen printed display driver circuits, based on organic electrochemical transistors (OECTs), and their monolithic integration with organic electrochromic displays (OECDs). Both OECTs and OECDs operate at low voltages and have similar device architectures, and, notably, they rely on the very same electroactive material as well as on the same electrochemical switching mechanism. This then allows us to manufacture OECT-OECD circuits in a concurrent manufacturing process entirely based on screen printing methods. By taking advantage of the high current throughput capability of OECTs, we further demonstrate their ability to control the light emission in traditional light-emitting diodes (LEDs), where the actual LED addressing is achieved by an OECT-based decoder circuit. The possibility to monolithically integrate all-screen printed OECTs and OECDs on flexible plastic foils paves the way for distributed smart sensor labels and similar Internet of Things applications.

Designing Inverters Based on Screen Printed Organic Electrochemical Transistors Targeting Low‐Voltage and High‐Frequency Operation

“…Organic electrochemical transistors (OECTs), [ 16,18–27 ] is currently one of the most studied organic electronic devices and is explored in various applications, such as in fully printed logic circuits, [ 16,26 ] active matrix addressed displays, [ 17 ] display driver circuits, [ 19 ] sensors, [ 22,23,28–33 ] neuromorphics, [ 24 ] just to name a few. OECTs can be manufactured via cost‐effective protocols using different printing techniques, such as screen printing, [ 19,21 ] 3D printing, [ 30 ] inkjet printing, [ 34 ] and other processes. [ 35,36 ] OECT‐based logic gates and circuits have also been investigated broadly, [ 35,37–40 ] where inverters as the elementary components of any combinational logic circuit play a key role.…”

Recent Technological Advances in Fabrication and Application of Organic Electrochemical Transistors

“…Even so, the screen‐printing technique is considered a simple, efficient, and low‐cost method for the fabrication of large area OECT‐based integrated circuits. [ 46,80–85 ] As shown in Figure 2b, coplanar OECTs were screen‐printed, where a printable UV‐curable electrolyte was sandwiched between the bottom channel and top‐gate electrode. [ 46 ] In such lateral OECTs, the printed PEDOT:PSS channel exhibited an ON/OFF ratio of ≈10 5 and switching times of ≈20 ms (ON‐to‐OFF) and 30 ms (OFF‐to‐ON), with a miniaturization of the OECT footprint down to ≈1 mm 2 (see Figure 2c).…”

“…Organic electrochromic displays (OECDs), in which the device architectures and electrochemical switching mechanism are similar to that of OECTs, have also been fabricated using screen printing in a concurrent manufacturing process. [ 81,86 ] The all‐screen printed OECTs and OECDs were monolithically integrated and manufactured on flexible plastic substrates for distributed smart sensor labels and targeted Internet of Things (IoT) applications. Thus, screen‐printing technique makes it possible to develop large‐scale logic circuits with arrays of sensors for wearable devices.…”

“…[ 55,187 ] To realize OECT‐based digital circuits, many attempts have been reported to apply OECTs in inverters, NAND, oscillators, signal amplifier and wheatstone bridge logic circuits, etc. [ 82,188,189 ] Up to now, various technologies have been developed to manufacture different large‐area and high‐volume OECT‐based logic circuits, including screen‐printing, [ 46,79,81,86 ] photolithographic patterning, [ 190 ] nanoimprinting, [ 61,112 ] inkjet printing, [ 75,95 ] aerosol‐jet‐printing, [ 89 ] cut‐and‐stick method, [ 191 ] etc.…”

“…The OECTs used as drivers for display was also demonstrated by controlling the light emission in traditional LEDs, in which actual LED addressing was implemented by an OECT decoder. [ 81 ] The monolithic integration of OECT‐based display driver circuits and displays presents a promising application in smart labels within packaging and IoT.…”