Printed and flexible organic and inorganic memristor devices for non-volatile memory applications

Abstract

Abstract The electronics market is highly competitive and driven by consumers desire for the latest and most sophisticated devices at the lowest cost. In the last decade there has been increasing interest in printing electronic materials on lightweight and flexible substrates such as plastics and fabrics. This not only lowers fabrication and capital costs but also facilitates many new applications, such as flexible displays and wearable electronics. The printing of computer memory is also desirable since many of these applications require memory to store and process information. In addition, there is now an international effort to develop new types of computer memory that consume ultra-low levels of power. This is not only to lower energy usage worldwide, which is important for reducing CO2 emissions, but it also enables a longer period between the re-charging of devices such as mobile phones, music players and fitness bands. Memory that is non-volatile is an obvious choice since it does not consume power to retain information like conventional SRAM and DRAM. Memristors (or memory resistor) are a new type of memory that are intrinsically non-volatile in nature. Their simple two-terminal architecture, easy method of fabrication and low power consumption means they have received much attention from both the research community and industry. Devices with the lowest fabrication costs are made from organic or hybrid (organic–inorganic) composite materials because of the ability to use low-cost solution processing methods with the advantages of large area deposition under vacuum-free and room temperature ambient conditions. Memristors have excellent device properties, including a large resistance Off/On ratio (up to 5 orders of magnitude), fast switching speeds (less than 15 ns), long endurance (over 1012 cycles), long data storage retention time (∼10 years) and high scalability down to nanoscale dimensions. In this article we review progress in the field of printed and flexible memristor devices and discuss their potential across a wide range of applications.