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

Journal Article · Tue May 28 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4808337· OSTI ID:22162979

Chauhan, K. N.; Riffe, D. M.; Everett, E. A.; Kim, D. J.; Yang, H. ^[1]; Shen, F. K. ^[2]

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1. Physics Department, Utah State University, Logan, Utah 84322-4415 (United States)
2. Center for Surface Analysis and Applications, Utah State University, Logan, Utah 84322-4415 (United States)

Using 800 nm, 25-fs pulses from a mode locked Ti:Al{sub 2}O{sub 3} laser, we have measured the ultrafast optical reflectivity of MBE-grown, single-layer In{sub 0.4}Ga{sub 0.6}As/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 excited carrier density, the capture rate decreases; this slowing of the dynamics is attributed to Pauli state blocking within the InGaAs quantum layer.

• OSTI ID: 22162979
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 20; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ANNEALING
ARSENIC COMPOUNDS
CAPTURE
CARRIER DENSITY
CARRIERS
CHANNELING
DEPLETION LAYER
DEPOSITION
EFFICIENCY
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LASER RADIATION
MOLECULAR BEAM EPITAXY
PULSES
QUANTUM DOTS
REFLECTIVITY
SEMICONDUCTOR MATERIALS
THICKNESS