Glass Reflections
Cambridge 7th to 9th September

Presenting Author:
David Wright

article posted 6 May 2015

David Wright

Prof C David Wright, FIEE, is Professor of Electronic Engineering and leader of the University of Exeter's 'Functional Materials' research theme that brings together 150 researchers from Engineering & Physics, working in novel materials design, development and application. David brings internationally leading expertise in exploiting the properties of memory materials and in particular chalcogenides, to deliver new functionalities. This work has led to very high-profile recent publications and numerous invited talks at prestigious conferences. David has participated in numerous EU Framework projects, leading the FP6 Project on Terabyte Memories.

Exploiting Mixed-Mode Optical-Electrical Functionality in Chalcogenide Glasses

C. David Wright1*, Santiago García-Cuevas Carrillo1, Peiman Hosseni2, Harish Bhaskaran2

Phase-change chalcogenide alloys, such as Ge2Sb2Te5 (GST), have very different optical and electrical properties in their amorphous and crystalline phases. The fact that such alloys can be switched, optically or electrically, between such phases rapidly and repeatedly means that they have much potential for applications that exploit this inherent "mixed-mode" functionality, i.e. we might excite (switch) them electrically but sense (read) optically, or vice-versa. One remarkable application of this mixed-mode concept is the recent demonstration of chalcogenide displays, in which electrical excitation of ultra-thin films of GST was used to provide novel non-volatile solid-state colour electronic displays [1].

Another important technological application is that of light modulation, in which thin-films of GST, or a similar phase-change chalcogenide, are combined with metamaterial arrays to provide high-performance thin-film electro-optic (spatial light) modulators [2]. In this paper we expand on this idea of combining metamaterial arrays and chalcogenide thin-films to enhance and exploit the mixed-mode electro-optic properties of phase-change thin films, concentrating in particular on approaches to the provision of practicable display and absorber/modulator devices.


[1] P Hosseini, C D Wright and H Bhaskaran, An optoelectronic framework enabled by low-dimensional phase-change films, Nature 511, 206-211 (2014)

[2] B Gholipour , J Zhang , K F MacDonald , D W Hewak and N I Zheludev, An All-Optical, Non-volatile, Bidirectional, Phase-Change Meta-Switch, Adv. Mater. 25, 3050-3054 (2013)


1 Department of Engineering, University of Exeter, EX4 4QF, UK.

2 Department of Materials Science, University of Oxford, OX1 3PH, UK