Jitendra K.Behera, WeiJieWang, XilinZhou, ShanGuan, WuWeikang, Yang A.Shengyuan and Robert E.Simpson. (2020) Resistance modulation in Ge2Sb2Te5. Journal of Materials Science & Technology, doi:10.1016/j.jmst.2020.03.016


Author links open overlay pa

J. C. Martinez, L. Lu, J. Ning, W. Dong, T. Cao, and R. E. Simpson. The Origin of Optical Contrast in Sb2Te3-Based Phase-Change Materials. Phys. Stat. Sol. (b), 0(0):1900289, 2019/10/09 2019

T. Cao, K. Liu, L. Lu, H.-C. Chui, and R. E. Simpson. Chalcogenide–gold dual-layers coupled to gold nanoparticles for reconfigurable perfect absorption. Nanoscale, Online, 2019

R. E. Simpson. The changing phase of data storage. Nature Nanotechnology, In Press, 2019

T. Cao, K. Liu, L. Lu, H.-C. Chui, and R. E. Simpson. Large-area broadband near-perfect absorption from a thin chalcogenide film coupled to gold nanoparticles. Appl. Mater. Interfaces, 2019

K. V. Sreekanth, Q. Ouyang, S. Sreejith, S. Zeng, W. Lishu, E. Ilker, W. Dong, M. ElKabbash, Y. Ting, C. T. Lim, M. Hinczewski, G. Strangi, K. Yong, t. R. E, and R. Singh. Phase-change- material-based low-loss visible-frequency hyperbolic metamaterials for ultrasensitive label-free biosensing. Advanced Optical Materials, 7(12):1900081, 2019

T. Cao, L. Mao, Y. Qiu, L. Lu, A. Banas, K. Banas, R. E. Simpson, and H.-C. Chui. Fano resonance in asymmetric plasmonic nanostructure: Separation of sub-10 nm enantiomers. Advanced Optical Materials, 7(3):1801172, 2019

K. V. Sreekanth and R. E. Simpson. Super-collimation and negative refraction in hyperbolic van der waals superlattices. Optics Communications, 440:150 – 154, 2019

L. Lu, W. Dong, J. K. Behera, L. T. Chew, and R. E. Simpson. Inter-diffusion of plasmonic
metals and phase change materials. J. Optics-UK, 54(4):2814–2823, 2019

W. Dong, H. Liu, J. K. Behera, L. Lu, R. J. H. Ng, K. V. Sreekanth, X. Zhou, J. K. Yang, and R. E. Simpson. Wide band gap phase change material tuned visible photonics. Advanced Functional Materials, (1806181), 2019


W. Dong, T. Cao, K. Liu, and R. E. Simpson. Flexible omnidirectional and polarisation-insensitive broadband plasmon-enhanced absorber. Nano Energy, 2018

T. Cao, X. Zhang, W. Dong, L. Lu, X. Zhou, X. Zhuang, J. Deng, X. Cheng, G. Li, and R. E. Simpson. Tuneable thermal emission using chalcogenide metasurface. Advanced Optical Materials, page 1800169, 2018

L. Chew, W. Dong, A. Ranjan, J. K. Behera, L. Lu, and R. E. Simpson. Electric field effects in chalcogenides. MRS Advances, pages 1–7, 2018

L. Lu, R. E. Simpson, and t. K. Valiyaveedu. Active hyperbolic metamaterials: progress, materials and design. Journal of Optics, 20(10):103001, 2018

T. Cao, L. Mao, Y. Qiu, L. Lu, A. Banas, K. Banas, R. E. Simpson, and H.-C. Chui. Fano resonance in asymmetric plasmonic nanostructure: Separation of sub-10 nm enantiomers. Advanced Optical Materials, 7(3):1801172, 2019

Y. Meng, J. K. Behera, Y. Ke, L. Chew, Y. Wang, Y. Long, and R. E. Simpson. Design of a 4-level active photonics phase change switch using VO2 and Ge2Sb2Te5. Applied Physics Letters, 113(7):071901, 2018

Y. Meng, J. K. Behera, S. Wen, R. E. Simpson, J. Shi, L. Wu, Z. Song, J. Wei, and Y. Wang. Ultra- fast multilevel optical tuning with CSb2Te3 thin films. Advanced Optical Materials, 6(17):1800360, 2018

K. V. Sreekanth, W. Dong, Q. Ouyang, S. Sreejith, M. El Kabbash, C. T. Lim, G. Strangi, K.-T. Yong, R. E. Simpson, and R. Singh. Large area silver-stibnite nanoporous plasmonic films for label-free biosensing. ACS Applied Materials & Interfaces, 2018

J. K. Behera, X. Zhou, A. Ranjan, and R. Simpson. Sb2Te3 and its superlattices: Optimization by statistical design. ACS Applied Materials & Interfaces, 10(17):15040–15050, 2018

W. Dong, Y. Qiu, X. Zhou, A. Banas, K. Banas, M. B. Breese, T. Cao, and R. E. Simpson. Tunable mid-infrared phase-change metasurface. Advanced Optical Materials, page 1701346, 2018

O. Roscioni, P. Branicio, J. Kalikka, X. Zhou, and R. Simpson. Local structure of Ge2Sb2Te5 during crystallization under pressure. Applied Physics Letters, 112(15):151901, 2018


JK Behera, X Zhou, J Tominaga, RE Simpson, “Laser switching and characterisation of chalcogenides: systems, measurements, and applicability to photonics”, Optical Materials Express 7 (10), 3741-3759, 2017

X Zhou, JK Behera, S Lv, L Wu, Z Song, RE Simpson, “Avalanche atomic switching in strain engineered Sb2Te3–GeTe interfacial phase-change memory cells”, Nano Futures 1 (2), 025003, 2017 (This paper was selected by the journal editors to be republished in a 2017 highlights edition. The highlights collection showcases exceptional work published in 2017– please see here.)

W Dong, L Lu, LT Chew, X Zhou, T Cao, RE Simpson “Phase change material tuned metamaterials”, Optics and Photonics Japan, 31aON1, 2017

LT Chew, W Dong, L Liu, X Zhou, J Behera, H Liu, KV Sreekanth, L Mao, … “Chalcogenide active photonics”, Active Photonic Platforms IX 10345, 103451B, 2017


Janne Kalikka, Xilin Zhou, Jitendra Behera, Giacomo Nannicini and Robert E Simpson “Evolutionary design of interfacial phase change van der Waals heterostructures” Nanoscale, 2016 DOI: 10.1039/C6NR05539G

W Dong, M Krbal, J Kalikka, XY Chin, B Gholipour, C Soci, PJ Fons, Kirill V Mitrofanov, Lujie Chen, and Robert E Simpson “Enhanced Sb2S3 crystallisation by electric field induced silver doping” Thin Solid Films 616, 80-85

Xilin Zhou, Yonghua Du, Jitendra K. Behera, Liangcai Wu, Zhitang Song, and Robert E. Simpson, Oxygen Tuned Local Structure and Phase-Change Performance of Germanium Telluride, ACS Appl. Mater. Interfaces, 2016. doi: 10.1021/acsami.6b05071

Janne Kalikka, Xilin Zhou, Eric Dilcher, Simon Wall, Ju Li & Robert E. Simpson, Strain-engineered diffusive atomic switching in two-dimensional crystals, Nature Communications, 7, 11983, doi:10.1038/ncomms11983

Weiling Dong, Yimei Qiu, Joel KW Yang, Robert E Simpson, Tun Cao, Wideband Absorbers in the Visible with Ultrathin Plasmonic-phase Change Material Nanogratings, J. Phys. Chem. C, 2016, 120 (23), pp 12713–12722

Xilin Zhou,  Janne Kalikka, Xinglong Ji, Liangcai Wu, Zhitang Song, Robert E Simpson. Phase-Change Memory Materials by Design: A Strain Engineering Approach, Advanced Materials, Feb, 2016


L Waldecker, TA Miller, M Rudé, R Bertoni, J Osmond, V Pruneri, R E Simpson, Simon Wall. Time-domain separation of optical properties from structural transitions in resonantly bonded materials, Nature materials 14 (10), 991-995 2015

Layered 2D crystals by design: optimisation of Sb2Te3-GeTe van der Waals superlattices, J Kalikka, X Zhou, G Nannicini, RE Simpson

MB Carlson, KK Yau, RE Simpson, MP Short, 3D Printing and Additive Manufacturing 2 (3), 123-130 2015

X. Zhou, W. Dong, H. Zhang, and R. E. Simpson. A zero density change phase change memory material: Gete-o structural characteristics upon crystallisation. Scientific Reports, 5, 2015.

M. Rude, R. E. Simpson, R. Quidant, V. Pruneri, and J. Renger. Active control of surface plasmon waveguides with a phase change material. ACS Photonics, 2015.


P. Fons, P. Rodenbach, K. V. Mitrofanov, A. V. Kolobov, J. Tominaga, R. Shayduk, A. Giussani, R. Calarco, M. Hanke, H. Riechert, et al. Picosecond strain dynamics in ge 2 sb 2 te 5 monitored by time-resolved x-ray diffraction. Physical Review B, 90(9):094305, 2014.

C.-C. Huang, F. Al-Saab, Y. Wang, J.-Y. Ou, J. C. Walker, S. Wang, B. Gholipour, R. E. Simpson, and D. W. Hewak. Scalable high-mobility mos 2 thin films fabricated by an atmospheric pressure chemical vapor deposition process at ambient temperature. Nanoscale, 6(21):12792–12797, 2014.

L. Waldecker, T. A. Miller, M. Rude, R. Bertoni, J. Osmond, V. Pruneri, R. Simpson, R. Ernstorfer, and S. Wall. Decoupled optical response and structural transition in phase change materials. arXiv preprint arXiv:1412.0901, 2014.

S. Wall, L. Waldecker, T. A. Miller, R. Ernstorfer, V. Pruneri, M. Rude, and R. Simpson. Competition between thermal and non-thermal processes during femtosecond switching of phase change materials. In International Conference on Ultrafast Phenomena, pages 07–Mon. Optical Society of America, 2014.

T Cao, C Wei, RE Simpson, L Zhang, MJ Cryan, Fast tuning of Fano resonance in metal/phase-change materials/metal metamaterials, Optical Materials Express 4 (9), 1775-1786 2014

T Cao, C Wei, RE Simpson, L Zhang, MJ Cryan, Fast Tuning of Double Fano Resonance Using A Phase-Change Metamaterial Under Low Power Intensity, Scientific reports 4 3 2014

T Cao, C Wei, RE Simpson, L Zhang, MJ Cryan, Broadband Polarization-Independent Perfect Absorber Using a Phase-Change Metamaterial at Visible Frequencies, Scientific reports 4 1 2014


T Cao, L Zhang, RE Simpson, C Wei, MJ Cryan, Strongly tunable circular dichroism in gammadion chiral phase-change metamaterials, Optics express 21 (23), 27841-27851 3 2013

M Rudé, J Pello, RE Simpson, J Osmond, G Roelkens, Optical switching at 1.55 μm in silicon racetrack resonators using phase change materials, Applied Physics Letters 103 (14), 141119 3 2013

T Cao, C Wei, RE Simpson, L Zhang, MJ Cryan, Rapid phase transition of a phase-change metamaterial perfect absorber, Optical Materials Express 3 (8), 1101-1110 3 2013

N Formica, DS Ghosh, A Carrilero, TL Chen, R Simpson, V Pruneri. Ultra-stable and atomically smooth ultra-thin silver films grown on a copper seed layer. ACS Appl. Mater. Interfaces, 5 (8), 3048–3053, 2013.

T Cao, RE Simpson, MJ Cryan, Study of tunable negative index metamaterials based on phase-change materials. JOSA B 30 (2), 439-444, 2013.

T Cao, L Zhang, RE Simpson, MJ Cryan, Mid Infrared Tunable Polarization-Independent Perfect Absorber Using A Phase-Change Metamaterial. JOSA B, Vol. 30 (60), 1580-1585, 2013.


F. R. M. Adikan, S.R. Sandoghchi, Wu Yi Chong, R. E. Simpson, M. A. Mahdi, A. S. Webb, J. C. Gates, C Holmes. Direct UV Written Optical Waveguides in Flexible Glass Flat Fiber Chips. IEEE J. Sel. Top. Quant. Electron. 18 (5), 1534-1539, 2012

R. E. Simpson, P. Fons, A. V. Kolobov, M. Krbal, and J. Tominaga. Enhanced crystallization of GeTe from an Sb2Te3 template. App. Phys. Lett., 100(2):021911–021911–4, 2012.


F. Mahamd Adikan, S. Sandoghchi, W. Chong, R. Simpson, M. Mahdi, A. Webb, J. Gates, and C. Holmes. Direct uv written optical waveguides in flexible glass flat fiber chips. Selected Topics in Quantum Electronics, IEEE Journal of, 99, 2011.

M. Krbal, J. Tominaga, A. V. Kolobov, P. Fons, R. E. Simpson, T. Matsunaga, N. Yamada, and T. Uruga. The local atomic order of crystalline Ge8Sb2Te11 across the ferroelectric to paraelectric transition. Phys. Rev. B, 84:104106, 2011.

J. Tominaga, R. E. Simpson, P. Fons, and A. V. Kolobov. Electrical-field induced giant magnetoresistivity in (non-magnetic) phase change films. Appl. Phys. Lett., 99:152105, 2011. ( HIGHLIGHT in Nature Nanotechnology, “Better Together”, November 2011)

R. E. Simpson, P. Fons, A. Kolobov, T. Fukaya, M. Krbal, T. Yagi, and J. Tominaga. Interfacial phase- change memory. Nature Nanotechnology, 6(8), 2011.

X. Biquard, M. Krbal, A. V. Kolobov, P. Fons, R. E. Simpson, B. Hyot, B. Andr ́e, J. Tominaga, and T. Uruga. Effect of doping on global and local order in crystalline gete. Appl. Phys. Lett., 98(23):231907– 231910, 2011.


R. E. Simpson, P. Fons, A. Kolobov, M. Krbal, and J. Tominaga. Seeded crystallisation and enhanced phase-change materials. MRS, 2010.

M. Krbal, A. V. Kolobov, B. Hyot, B. Andre, P. Fons, R. E. Simpson, T. Uruga, H. Tanida, and J. Tominaga. Amorphous InSb: Longer bonds yet higher density. J. Appl. Phys., 108(2), 2010.

R. E. Simpson, P. Fons, X. Wang, A. Kolobov, T. Fukaya, and J. Tominaga. Non-melting super-resolution near-field apertures in Sb–Te alloys. Applied Physics Letters, 97, 2010.

R. E. Simpson, M. Krbal, P. Fons, A. Kolobov, J. Tominaga, T. Uruga, and H. Tanida. Toward the ultimate limit of phase change in Ge2Sb2Te5. Nano letters, 10(2) 414-419, 2010.

R. E. Simpson, M. Krbal, P. Fons, A. Kolobov, T. Uruga, H. Tanida, and J. Tominaga. Stress limited scaling of Ge2Sb2Te5. MRS Proceedings, 1251(1), 2010.


A. Kolobov, P. Fons, M. Krbal, R. Simpson, S. Hosokawa, T. Uruga, H. Tanida, and J. Tominaga. Liquid GeSbTe studied by extended x-ray absorption. Appl. Phys. Lett., 95:241902, 2009.

R. E. Simpson, P. Fons, A. Kolobov, M. Kuwahara, and J. Tominaga. Crystallization of Bi doped Sb8Te2. Jpn J Appl Phys, 48(3), 2009.

J. Tominaga, T. Shima, P. Fons, R. Simpson, M. Kuwahara, and A. Kolobov. What is the origin of activation energy in phase-change films? Jpn. J. Appl. Phys, 48(3):03A053, 2009.

M Kuwahara, O Suzuki, K Tsutsumi, T Yagi, N Taketoshi, H Kato, RE Simpson,  Michio Suzuki, Junji Tominaga, Tetsuya Baba. Measurement of Refractive Index, Specific Heat Capacity, and Thermal Conductivity for Ag6.0In4.5Sb60.8Te28.7 at High Temperature, Jpn J Appl Phys 48 (5), 05EC02-05EC02-3


R. E. Simpson, D. Hewak, P. Fons, J. Tominaga, S. Guerin, and B. Hayden. Reduction in crystallization time of Sb: Te films through addition of Bi. Applied Physics Letters, 92(14), 2008.

MSB Darby, RE Simpson, TC May-Smith, DW Hewak, RW Eason. Influence of deposition parameters on composition and refractive index of femtosecond and nanosecond pulsed laser deposited gallium lanthanum oxysulphide. Journal of Non-Crystalline Solids 354 (40), 4582-4588

R. E. Simpson. Chalcogenide thin film materials for next generation data storage. PhD thesis, University of Southampton, 2008.


R. E. Simpson, A. Mairaj, C. Huang, K. Knight, N. Sessions, M. Hassan, D. Hewak, and R. Curry. Electrical phase change of Ga: La: S: Cu films. Electronics Letters, 43(15), 2007.