Carrier Capture Dynamics of Single InGaAs/GaAs Quantum-Dot Layers

Authors

K. N. Chauhan
D. Mark Riffe, Utah State UniversityFollow
E. A. Everett
D. J. Kim
H. Yang
F. K. Shen, Utah State University

Document Type

Article

Journal/Book Title/Conference

Journal of Applied Physics

Volume

113

Publisher

AIP

Publication Date

2013

Abstract

Using 800 nm, 25-fs pulses from a mode locked Ti:Al₂O₃ laser, we have measured the ultrafast opticalreflectivity of MBE-grown, single-layer In_0.4Ga_0.6As/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 140 fs, 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 excitedcarrier density, the capture rate decreases; this slowing of the dynamics is attributed to Pauli state blocking within the InGaAs quantum layer.

Recommended Citation

Chauhan, K. N.; Riffe, D. Mark; Everett, E. A.; Kim, D. J.; Yang, H.; and Shen, F. K., "Carrier Capture Dynamics of Single InGaAs/GaAs Quantum-Dot Layers" (2013). All Physics Faculty Publications. Paper 2021.
https://digitalcommons.usu.edu/physics_facpub/2021