Investigation of carrier dynamics in InAs/GaAsSb quantum dots with different silicon delta-doping levels

Journal Article · Thu Nov 10 04:00:00 EST 2016 · Semiconductor Science and Technology

DOI:https://doi.org/10.1088/0268-1242/31/12/125010· OSTI ID:1335215

Ban, Keun-Yong ^[1]; Kim, Yeongho ^[2]; Kuciauskas, Darius ^[3]; Bremner, Stephen P. ^[4]; Honsberg, Christiana B. ^[1]

---

1. Arizona State Univ., Tempe, AZ (United States). School of Electrical, Computer and Energy Engineering
2. Korea Research Inst. of Chemistry Technology (KRICT), Daejeon (Korea, Republic of). Division of Metrology for Future Technology
3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
4. Univ. of New South Wales, Sydney, NSW (Australia). School of Photovoltaic and Renewable Energy Engineering

The optical properties of InAs quantum dots (QDs) embedded in a GaAsSb matrix with different delta (d)-doping levels of 0, 2, 4, and 6 electrons per dot (e-/dot), incorporated to control the occupation of QD electronic states, are studied by photoluminescence (PL) spectroscopy. The time-resolved PL data taken at 10 K reveal that the increase of δ-doping density from 2 to 6 e^-/dot decreases the recombination lifetime of carriers at ground states of the QDs from 996 ± 36 to 792 ± 19 ps, respectively. Furthermore, the carrier lifetime of the sample with 4 e^-/dot is found to increase at a slower rate than that of the undoped sample as temperature increases above 70 K. An Arrhenius plot of the temperature dependent PL intensity indicates that the thermal activation energy of electrons in the QDs, required for carrier escape from the dot ground state to continuum state, is increased when the d-doping density is high enough (>4 e^-/dot). These results are attributed to the enhanced Coulomb interaction of electrons provided by the d-doping, leading to reduced thermal quenching of the PL.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1335215
• Report Number(s): NREL/JA--5J00-67534
• Journal Information: Semiconductor Science and Technology, Journal Name: Semiconductor Science and Technology Journal Issue: 12 Vol. 31; ISSN 0268-1242
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
carrier dynamics
delta-doping
intermediate band solar cells
quantum dots