TY - JOUR
T1 - Optical properties of composition-controlled three-dimensional Si/Si 1-xGex nanostructures
AU - Tsybeskov, Leonid
AU - Kamenev, Boris V.
AU - Baribeau, Jean Marc
AU - Lockwood, David J.
N1 - Funding Information:
Manuscript received November 1, 2005; revised August 29, 2006. This work was supported in part by the National Science Foundation (NSF), in part by Intel Corporation, and in part by the Foundation at New Jersey Institute of Technology (NJIT). L. Tsybeskov is with the Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ 07102 USA (e-mail: [email protected]). B. V. Kamanev is with Rudolph Technologies, Flanders, NJ 07836 USA. J.-M. Baribeau and D. J. Lockwood are with the Institute for Microstructural Sciences, National Research Council, Ottawa, ON K1A 0R6, Canada. Digital Object Identifier 10.1109/JSTQE.2006.884061
PY - 2006/11
Y1 - 2006/11
N2 - We report the Raman, continuous-wave (CW), and time-resolved photoluminescence (PL) measurements in a series of multilayer Si/Si 1-xGex samples with an island-like morphology and precise control over the chemical composition in the range of 0.096 ≤ x ≤ 0.61. In the samples with x continuously increasing from 0.096 to 0.55, an increase in the intensity of the Raman signal related to the Ge-Ge vibrations correlates with a red shift in the PL peak position and an increase in the activation energy of the PL thermal quenching. Time-resolved PL measurements reveal 1-10-ms PL components. The highest observed PL quantum efficiency (better than 1 % at low temperature) is found in the samples with x ∼ 0.5, where the carrier recombination presumably occurs at sharp Si/SiGe interfaces that exhibit type-II band alignment, with a small (to the order of several milli-electron volts) barrier for electrons and deep potential wells for the holes localized within the Ge-rich Si1-xGex islands. In the samples with Ge concentration close to 0.61, we observe a strong, step-like increase in the strain, and a significant evidence of strain-induced SiGe interdiffusion that results in the decrease in the PL quantum efficiency.
AB - We report the Raman, continuous-wave (CW), and time-resolved photoluminescence (PL) measurements in a series of multilayer Si/Si 1-xGex samples with an island-like morphology and precise control over the chemical composition in the range of 0.096 ≤ x ≤ 0.61. In the samples with x continuously increasing from 0.096 to 0.55, an increase in the intensity of the Raman signal related to the Ge-Ge vibrations correlates with a red shift in the PL peak position and an increase in the activation energy of the PL thermal quenching. Time-resolved PL measurements reveal 1-10-ms PL components. The highest observed PL quantum efficiency (better than 1 % at low temperature) is found in the samples with x ∼ 0.5, where the carrier recombination presumably occurs at sharp Si/SiGe interfaces that exhibit type-II band alignment, with a small (to the order of several milli-electron volts) barrier for electrons and deep potential wells for the holes localized within the Ge-rich Si1-xGex islands. In the samples with Ge concentration close to 0.61, we observe a strong, step-like increase in the strain, and a significant evidence of strain-induced SiGe interdiffusion that results in the decrease in the PL quantum efficiency.
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U2 - 10.1109/JSTQE.2006.884061
DO - 10.1109/JSTQE.2006.884061
M3 - Article
AN - SCOPUS:33845678017
SN - 1077-260X
VL - 12
SP - 1579
EP - 1584
JO - IEEE Journal on Selected Topics in Quantum Electronics
JF - IEEE Journal on Selected Topics in Quantum Electronics
IS - 6
ER -