800 meV localization energy in GaSb/GaAs/Al0.3Ga0.7As quantum dots

Nowozin, Tobias; Bonato, Leo; Högner, A.; Wiengarten, Alissa; Bimberg, D.; Lin, Wei-Hsun; Lin, Shih‐Yen; Reyner, Charles J.; Liang, Baolai; Huffaker, Diana L.

doi:10.1063/1.4791678

Cited by 41 publications

(23 citation statements)

References 27 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[10] In previous measurements, σ 1 has been observed to vary over six orders of magnitude. [11] From this observation follows that a reliable method for engineering the cross-section would represent a valuable tool for the extension of hole retention time in QDs. In practice, crosssection engineering is achieved by acting on the structural and electronic properties of the QDs.…”

Section: Introductionmentioning

confidence: 96%

MOVPE‐Growth of InGaSb/AlP/GaP(001) Quantum Dots for Nanoscale Memory Applications

Sala

Arikan

Bonato

et al. 2018

Physica Status Solidi (b)

View full text Add to dashboard Cite

The structural and optical properties of InGaSb/GaP(001) type‐II quantum dots (QDs) grown by metalorganic vapor phase epitaxy (MOVPE) are studied. Growth strategies as growth interruption (GRI) after deposition of InGaSb and Sb‐flush prior to QD growth are used to tune the structural and optical properties of InGaSb QDs. The Sb‐flush affects the surface diffusion leading to more homogeneous QDs and to a reduction of defects. A ripening process during GRI occurs, where QD size is increased and QD‐luminescence remarkably improved. InGaSb QDs are embedded in GaP n + p‐diodes, employing an additional AlP barrier, and characterized electrically. A localization energy of 1.15 eV for holes in QDs is measured by using deep‐level transient spectroscopy (DLTS). The use of Sb in QD growth is found to decrease the associated QD capture cross‐section by one order of magnitude with respect to the one of In0.5Ga0.5As/GaP QDs. This leads to a hole storage time of almost 1 h at room temperature, which represents to date the record value for MOVPE‐grown QDs, making MOVPE of InGaSb/GaP related QDs a promising technology for QD‐based nano‐memories.

show abstract

Section: Introductionmentioning

confidence: 96%

MOVPE‐Growth of InGaSb/AlP/GaP(001) Quantum Dots for Nanoscale Memory Applications

Sala

Arikan

Bonato

et al. 2018

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…The value of E β used is consistent with values that have been previously measured in GaSb/GaAs QDs. 7 It can be seen that our model successfully replicates the general behavior of OICD seen in this MBEgrown sample [ Fig. 6(a) inset].…”

Section: Modelingmentioning

confidence: 61%

“…This property makes GaSb/GaAs QD/QRs candidates for use in solar cells. 4,5 Large confinement energies, 6,7 negligible charging barriers, 8 and strong three-dimensional carrier confinement in GaSb/GaAs QD/QRs make them promising for use in memory devices. 9,10 The Aharanov-Bohm effect has already been observed in other type-II QD systems, 11,12 and the large confinement potential of GaSb/GaAs QD/QRs makes them a favorable candidate for observation of such effects at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

et al. 2013

View full text Add to dashboard Cite

We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports.

show abstract

“…However, it is unlikely that the ultimate goal of 10 years of storage time will be achieved using GaAs‐based memories due to the small localization energy of the holes in the QDs. According to both calculations and deep level transient spectroscopy (DLTS) measurements, GaP‐based materials have the potential to achieve non‐volatility defined as 10 y storage time. Therefore, GaP‐based resonant tunnel structures have been designed.…”

Section: Samplesmentioning

confidence: 99%

Transparency Engineering in Quantum Dot‐Based Memories

Arikan

Cottet

Nowozin

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

Quantum dot (QD) based memories offer new functionalities as compared to present main stream ones by combining the advantages of DRAM (fast access and write/erase time, good endurance) and Flash memories (long storage time). The present storage times in such memories are demonstrated to be several days at room temperature for GaP-based devices, while write times as short as picoseconds are possible. There exists however a trade-off between storage time and erase time. To eliminate this trade-off, resonant tunneling effects in single or double quantum well structures are studied here as a promising approach. The quantum well structures based on GaAs/ Al 0.9 Ga 0.1 As and GaP/AlP quantum wells inserted in QD-based memories are designed and simulated using a Schrödinger-Poisson solver and nonequilibrium Green's functions (NEGF) to calculate the transparency at a given voltage. By choosing the width of the quantum wells, precise positioning of their energy levels allows for transparency engineering. Our simulations show an increase in transparency by at least 7 orders of magnitude at resonance, leading indeed to sufficiently fast erase times, thus solving the trade-off problem.

show abstract

800 meV localization energy in GaSb/GaAs/Al0.3Ga0.7As quantum dots

Cited by 41 publications

References 27 publications

MOVPE‐Growth of InGaSb/AlP/GaP(001) Quantum Dots for Nanoscale Memory Applications

MOVPE‐Growth of InGaSb/AlP/GaP(001) Quantum Dots for Nanoscale Memory Applications

Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

Transparency Engineering in Quantum Dot‐Based Memories

Contact Info

Product

Resources

About