Temperature-dependent modulated reflectance of InAs/InGaAs/GaAs quantum dots-in-a-well infrared photodetectors

Journal Article · Tue Apr 14 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4917204· OSTI ID:22402843

Čechavičius, B.; Rimkus, A.; Pozingytė, E.; Kavaliauskas, J.; Valušis, G. ^[1]; Li, L. H.; Linfield, E. H. ^[2]

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1. Semiconductor Physics Institute, Center for Physical Sciences and Technology, A. Goštauto 11, LT-01108 Vilnius (Lithuania)
2. School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

We present a photoreflectance (PR) study of multi-layer InAs quantum dot (QD) photodetector structures, incorporating InGaAs overgrown layers and positioned asymmetrically within GaAs/AlAs quantum wells (QWs). The influence of the back-surface reflections on the QD PR spectra is explained and a temperature-dependent photomodulation mechanism is discussed. The optical interband transitions originating from the QD/QW ground- and excited-states are revealed and their temperature behaviour in the range of 3–300 K is established. In particular, we estimated the activation energy (∼320 meV) of exciton thermal escape from QD to QW bound-states at high temperatures. Furthermore, from the obtained Varshni parameters, a strain-driven partial decomposition of the InGaAs cap layer is determined.

• OSTI ID: 22402843
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
ALUMINIUM ARSENIDES
BOUND STATE
DECOMPOSITION
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
GALLIUM ARSENIDES
INDIUM ARSENIDES
LAYERS
PHOTODETECTORS
QUANTUM DOTS
QUANTUM WELLS
REFLECTION
SPECTRAL REFLECTANCE
STRAINS
TEMPERATURE DEPENDENCE