Carrier capture dynamics of single InGaAs/GaAs quantum-dot layers

Authors

Kripa N. Chauhaun, Utah State University
D. Mark Riffe, Utah State UniversityFollow
Addison E. Everett, Utah State UniversityFollow
D. J. Kim, Utah State University
H Yang, Utah State University
F. K. Shen, Utah State University

Document Type

Article

Journal/Book Title/Conference

Journal of Applied Physics

Volume

113

Publication Date

2013

Abstract

Using 800nm, 25-fs pulses from a mode locked Ti:Al2O3 laser, we have measured the ultrafast optical reflectivity of MBE-grown, single-layer In0.4Ga0.6As/GaAs quantum-dot (QD) samples. The QDs are formed via two-stage Stranski-Krastanov growth: following initial InGaAs deposition at a relatively low temperature, self assembly of the QDs occurs during a subsequent higher temperature anneal. The capture times for free carriers excited in the surrounding GaAs (barrier layer) are as short as 140fs, indicating capture efficiencies for the InGaAs quantum layer approaching 1. The capture rates are positively correlated with initial InGaAs thickness and annealing temperature. With increasing excited carrier density, the capture rate decreases; this slowing of the dynamics is attributed to Pauli state blocking within the InGaAs quantum layer.

Comments

Published by the American Institute of Physics in Journal of Applied Physics. Publisher PDF is available for download through link above.

Recommended Citation

Carrier Capture Dynamics of Single InGaAs/GaAs Quantum-Dot Layers," K. N. Chauhan," D. M. Riffe, E. A. Everett, D. J. Kim, H. Yang, and K. K. Shen, J. Appl. Phys. 113, 203710 (2013) (doi.org/10.1063/1.4808337).