Title :
Conductivity of nanoporous InP membranes investigated using terahertz spectroscopy
Author :
Merchant, S.K.E. ; Lloyd-Hughes, J. ; Sirbu, L. ; Tiginyanu, I.M. ; Parkinson, P. ; Herz, L.M. ; Johnston, M.B.
Author_Institution :
Dept. of Phys., Univ. of Oxford, Oxford
Abstract :
We have investigated the conductivity of equilibrium and photoexcited electrons in nanoporous indium phosphide (InP) of various porosities and of two orientations: (100) and (111). We observed an enhanced transmission through the nanoporous samples compared with bulk InP, resulting from a suppression of the conductivity by the pores. The frequency-dependent conductivity was extracted numerically from the transmission data. We examined the dynamical conductivity of photoexcited carriers using optical-pump THz-probe spectroscopy. After the rapid photoexcitation of electrons, the time-resolved conductivity was observed to decay slowly, with carrier recombination lifetimes exceeding Ins for all (100)- and (111)-oriented samples.
Keywords :
indium compounds; membranes; nanoporous materials; optical pumping; submillimetre wave spectroscopy; bulk InP; carrier recombination lifetimes; dynamical conductivity; electron photoexcitation; equilibrium electrons; frequency-dependent conductivity; nanoporous InP membrane conductivity; nanoporous indium phosphide; optical-pump THz-probe spectroscopy; photoexcited carriers; photoexcited electrons; pore conductivity; terahertz spectroscopy; time-resolved conductivity; transmission data; Biomembranes; Conductivity; Data mining; Electrons; Frequency; Indium phosphide; Nanoporous materials; Optical sensors; Spectroscopy; Time domain analysis;
Conference_Titel :
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on
Conference_Location :
Cardiff
Print_ISBN :
978-1-4244-1438-3
DOI :
10.1109/ICIMW.2007.4516471
