Chalcogenide-based memory and logic for flexible electronics applications

Joint supervisors: Prof C D Wright, Prof M F Craciun
External partners: PragmatIC Ltd (Dr C Ramsdale); University of Southampton (Prof D Hewak)

Here we will explore the use of ultra-thin and 2D chalcogenide semiconductor materials for the provision of non-volatile, re-writable phase-change memories and logic suited to flexible electronics applications. The project is sponsored by PragmatIC (www.pragmatic.tech), who are developing ultra-low cost flexible integrated circuits (FlexICs) thinner than a human hair that can easily be embedded into everyday objects enabling smart packaging, smart labels and smart objects that interact with consumers and their environments. In preliminary work [1-3] we have already shown that both 2D and low-dimensional chalcogenide alloys are suited to use in flexible systems (in the former the phase-transition is between semimetal and semiconducting phases, in the latter between amorphous and crystalline phases). However, very significant challenges remain in terms of materials development and device design so as to meet the requirements (e.g. high numbers of switching cycles, low-energy switching, fast switching speed, true non-volatility, longevity) for real-world applications. In this project, therefore, we will address such challenges by developing (i) novel phase-change device configurations for integration into flexible electronics formats and (ii) new chalcogenide phase-change compositions, new 2D heterostructures and new low-temperature (physical vapour deposition) approaches to the large-area fabrication of 2D materials. The research for this project will be carried out primarily at Exeter, but with placement opportunities with PragmatIC at both their Cambridge (research) and NETPark Sedgefield (manufacturing) sites.

[1] Hosseini P, Wright CD, Bhaskaran H An optoelectronic framework enabled by low-dimensional phase-change films, Nature, 511, 206-211, DOI:10.1038/nature13487 (2014)

[2] Alkhalil F, Ramsdale C, Au Y Y, Zeimpekis I, Hewak D and Wright CD, Phase-Change Memory for Flexible Electronics, http://www-large-area-electronics.eng.cam.ac.uk/innoLAE2018, InnoLAE 2018 Conference (2018)

[3] Nagareddy VK, Octon T J, Townsend NJ, Russo S, Craciun MF and Wright CD, Humidity‐Controlled Ultralow Power Layer‐by‐Layer Thinning, Nanopatterning and Bandgap Engineering of MoTe2, Advanced Functional Materials, https://doi.org/10.1002/adfm.201804434 (2018)