Non-technical: The team at Ohio State University, through an accidental discovery under NSF, is undergraduate research funding, developed and advanced a new organic tunnel diode using a hybrid junction incorporating a thin metal oxide and a solution-based organic semiconductor atop. This patented device is the first such structure to genuinely exhibit selective tunneling at room temperature using a scalable printable process. The current versus voltage characteristics are unique amongst semiconductor devices, looking like a capital letter (N). So, unlike most devices, a line drawn through this (N) provides three intersections. The middle is unstable and unusable, but the first and third provide for a simple way to store 1-bit, a (0) or a (1), using a single tunnel diode with another circuit element, such as a second tunnel diode or transistor, as the load. This project builds upon previous advances by building a multi-institutional team (Wayne State University, Tampere University of Technology, Aalto University and Picosun) spanning two countries (USA and Finland). The properties of this thin metal oxide tunneling barrier are key to the discovered operation. This project seeks a new way to deposit this layer that would permit large area deposition across flexible substrates, reaching a meter wide. Through collaborations with Finnish industry, we will increase the competitiveness and position of US industry and advance the intelligence and functionality of organic electronics, solar cells, electronic printing and atomic layer deposition technology. Participation of industry and international collaborators will broaden the culture of innovation and focus the research output towards strategic commercialization.
Ohio State University (OSU) proposes a 3-year bi-national (USA, Finland) project to advance printed organic electronics, particularly using organic tunnel diodes (OTD) and circuits integrated with organic field effect transistors (OFET). Their unique negative differential resistance (NDR) will reduce OFET device count, while concurrently reducing power consumption. Energy thrifty circuits will be key for autonomously powered sensor nodes for a dense network of trillions of objects for the Internet of Things (IoT). International teaming with Tampere Univ. of Technology (TUT-Finland) and Picosun (Finland), an atomic layer deposition (ALD) tool manufacturer, will provide collaborative opportunities for large-area rapid roll-to-roll (R2R) technologies to prototypical scale-up of the existing fundamental studies while enhancing materials discovery and understanding. A key aim of this project is working with Wayne State University (WSU) for novel ALD precursor and oxidizer discovery and process development to explore non-stoichiometric ALD for metal oxide tunnel barriers with engineering oxygen vacancies (energy level of defects, density-of-states, etc.) that critically control OTD defect related tunneling processes and therefore device performance based on NDR. Advances by this team for the first conjugated polymer based tunnel diode circuitry using room temperature NDR enable new opportunities for low-power consumption portable circuitry (logic, memory and mixed-signal). NDR circuitry can provide (i) component count reduction (more computational power per unit area), (ii) lower power consumption (fewer devices per logic function). Tremendous benefits to society and humankind: 1) Low-cost, ultra-low power autonomous plastic electronic memory, logic and wireless systems; 2) Advanced high-K dielectrics compatible with the limited thermal budget of organics; 3) Understanding of defects and their role in tunneling transport through thin high-K dielectrics; 4) Large-area, R2R electronic printing for high volume production. Students and international exchange: A full-time graduate student will be directly supported here. REU supplements will supplement this team with 1-2 undergraduates, along with international scientific visitations.
