An experimental study of the direct-gap related optical transitions in strain-compensated Ge/Si0.15Ge0.85 multiple quantum wells (MQWs) is presented. These structures are of particular interest due to the proximity of Γ-type and L-type conduction band states and due to their type I band alignment. The samples were grown by low-energy plasma-enhanced CVD and consist of Ge MQWs with a large numbers of periods and good morphological quality grown onto thick graded Si1 - x Gex buffer layers. The transmission spectra, which shows clear evidence of excitonic transitions, are studied as a function of temperature in the 5-300 K range. Preliminary results of photocurrent measurements performed on the same structures using metal-semiconductor-metal contact are discussed. © 2008 Elsevier B.V. All rights reserved.
Bonfanti, M., Grilli, E., Guzzi, M., Chrastina, H., Isella, G., von Kaenel, H., et al. (2009). Direct gap related optical transitions in Ge/SiGe quantum wells. PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 41(6), 972-975 [10.1016/j.physe.2008.08.052].
Direct gap related optical transitions in Ge/SiGe quantum wells
GRILLI, EMANUELE ENRICO;GUZZI, MARIO;
2009
Abstract
An experimental study of the direct-gap related optical transitions in strain-compensated Ge/Si0.15Ge0.85 multiple quantum wells (MQWs) is presented. These structures are of particular interest due to the proximity of Γ-type and L-type conduction band states and due to their type I band alignment. The samples were grown by low-energy plasma-enhanced CVD and consist of Ge MQWs with a large numbers of periods and good morphological quality grown onto thick graded Si1 - x Gex buffer layers. The transmission spectra, which shows clear evidence of excitonic transitions, are studied as a function of temperature in the 5-300 K range. Preliminary results of photocurrent measurements performed on the same structures using metal-semiconductor-metal contact are discussed. © 2008 Elsevier B.V. All rights reserved.
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