Our paper, “Avalanche atomic switching in strain engineered Sb2Te3–GeTe interfacial phase-change memory cells” has been selected by the Nano Futures’ editors as a highlight of 2017. 12 papers from 2017 that highlight the novelty and exceptional standards of Nano Futures, were selected for the highlights collection. See here for more info.
- Jitendra Kumar Behera, Xilin Zhou, Alok Ranjan, Robert Edwardsimpson:Optimisation of phase change van der Waals structures by statistical design of experiments
- Li Tian Chew, Li Lu, Robert Simpson:Interfacial Damage in Phase Change Materials Tuned Optical Structures
- Li Lu, Ramon Paniagua-Dominguez, Vytautas Valuckas, Arseniy I. Kuznetsov, Robert E. Simpson:Novel chalcogenide as a material platform for tunable nanoantenna arrays in the visible and near infrared spectrum
- Jose Martinez, Weiling Dong, Robert Simpson:Optical response of chalcogenide phase-change materials
- Jing Ning, Robert Simpson, Yee Kan Koh:Electrical, optical and thermal properties of Sb2Te3 and related materials.
- Rob Simpson, Jitendra Behera, Janne Kallika, Xilin Zhou, “Active electronic and photonic materials by nanostructural design”
ACTAlab has had the following three papers accepted for presentation at the MRS Spring meeting April 2018:
- Metal Diffusion into Ge2Sb2Te5 and Implications for Photonics
- Electric Field Effects in Chalcogenides
- Novel chalcogenide as a material platform for tunable nanoantenna arrays in the visible and near infrared spectrum
Congratulations to ACTAlab postdoc, Dr Xilin Zhou, for winning the best poster award at the Materials Research Society Spring Meeting, which was held in Phoenix USA April 2017. Xilin’s poster discusses the atomic transitions involved in Sb2Te-GeTe superlattices. In particular Xilin showed through a combination of experiments and simulations that the activation energy for disordering of the GeTe layers decreases as more atoms switch, and this leads to an avalanche switching effect.
There were more than 1500 posters presented at the conference, and only 9 were honored with a Best Poster Award. The photograph below shows Xilin with the meeting chairs.
Our paper on the evolutionary design of interfacial phase change superlattices has been accepted for publication in RSC Nanoscale. See the just accepted paper here.
Congratulations to ACTAlab PhD student, Ms Weiling Dong, for winning the best poster award at the EPCOS conference, which was held at Trinity College, Cambridge, UK 5th-6th Sept. Weiling’s poster discusses the combination of plasmonic nanogratings and the phase change material Ge2Sb2Te5 to create structural colour. More details of Weiling’s work can be found here.
Today, Xilin Zhou’s paper, which discusses how oxygen doping influences the the local structure of GeTe, has been published in ACS Applied Materials and Interfaces.
Interestingly when oxygen is added into GeTe, the energy required to switch the material in a phase change random access memory cell is lowered, yet counter intuitively the crystallization temperature is increased by O doping. Previously we showed that there is zero change in density for O concentrations of about 5 at.%. We believe that this allows the material to be switched with a lower enthalpy change, hence explaining the energy efficient memory switching.
The paper is available here: http://pubs.acs.org/doi/abs/10.1021/acsami.6b05071
Weiling Dong, Jitendra Behera, and Rob Simpson will present three papers at EPCOS 2016 in Cambridge, UK. The conference will be held in September 2016.
The papers are:
- Wideband visible absorbers by Ge2Sb2Te5 and Al nanogratings, Weiling Dong, Yimei Qiu, Joel K.W. Yang, Robert E. Simpson, and Tun Cao
- Laser switching of nanostructured phase change materials, Jitendra K. Behera, Xilin Zhou, and Robert E. Simpson
- Genetic algorithm inspired design of Ge2Sb2Te5 structures, Robert E Simpson, Janne Kalikka, Jitendra K Behera, Giacomo Nannicini and Xilin Zhou
See you in Cambridge!
Our paper on the design of strain engineered chalcogenide superlattices has been published in Nature Communications. The paper presents the design rules for creating superlattices with switchable properties.
Ms Weiling Dong successfully passed her qualifying exam. Congratulations. She will now continue her research into chalcogenide materials actively tuned photonics.