Prof Michael Johnston: Publications

Characterisation of nanostructures via terahertz spectroscopy

Conference on Optoelectronic and Microelectronic Materials and Devices, Proceedings, COMMAD (2010) 23-24

Authors:

P Parkinson, HJ Joyce, X Xu, Q Gao, HH Tan, C Jagadish, LM Herz, MB Johnston

Abstract:

We have used terahertz spectroscopy to measure the conductivity and time-resolved photoconductivity of a range of semiconducting nanostructures. This article focuses on our recent terahertz conductivity studies on semiconductor nanowires and single walled carbon nanotubes. © 2010 IEEE.

Intense terahertz generation based on the photo-dember effect

Optics InfoBase Conference Papers (2010)

Authors:

G Klatt, F Hilser, W Chao, R Gebs, A Bartels, K Huska, U Lemmer, G Bastian, MB Johnston, M Fischer, J Faist, T Dekorsy

Abstract:

We demonstrate a new scheme for generating THz radiation based on the photo-Dember effect in lateral geometry. By micro-structuring a semiconductor surface we achieve strongly enhanced THz emission comparable to high-efficiency externally biased photoconductive emitters. © 2010 Optical Society of America.

The role of ultrafast torsional relaxation in the emission from polythiophene aggregates

Conference on Optoelectronic and Microelectronic Materials and Devices, Proceedings, COMMAD (2010) 117-118

Authors:

P Parkinson, C Müller, N Stingelin, MB Johnston, LM Herz

Abstract:

An understanding of aggregation effects in organic semiconductors is essential for their effective use in optoelectronic devices. Typically, the electronic dynamics in such systems are heavily dependant upon the aggregation state, and dynamics often occur on sub-nanosecond timescales. © 2010 IEEE.

Improved performance of GaAs-based terahertz emitters

IRMMW-THz 2010 - 35th International Conference on Infrared, Millimeter, and Terahertz Waves, Conference Guide (2010)

Authors:

C Headley, L Fu, P Parkinson, X Xu, J Lloyd-Hughes, C Jagadish, MB Johnston

Abstract:

We have improved the stability and performance of terahertz photoconductive (Auston) switches using a combination of (NH4)2S surface passivation and silicon nitride (Si3N4) encapsulation. The passivation and encapsulation processes increased the average terahertz power generated four-fold.

Intense terahertz generation based on the photo-Dember effect

Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference: 2010 Laser Science to Photonic Applications, CLEO/QELS 2010 (2010)

Authors:

G Klatt, F Hilser, W Chao, R Gebs, A Bartels, K Huska, U Lemmer, G Bastian, MB Johnston, M Fischer, J Faist, T Dekorsy

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