Growth and characterization of antimony-based quantum dots in GaP matrix for nanomemories

On the importance of antimony for temporal evolution of emission from self-assembled (InGa)(AsSb)/GaAs quantum dots on GaP(001)

“…The samples were grown by MOVPE in Stranski-Krastanov (SK) mode on GaP(001) substrates at the TU Berlin [25,26]. Such samples were also previously investigated by means of steady-state photoluminescence [34].…”

“…All samples include 5 ML-thick GaAs interlayer (IL), a crucial ingredient for the subsequent QD formation, as pointed out by Sala et al [25,36]. The sample having the IL only is referred to as S w/o , that labeled S with (S cap ) contains (InGa)(AsSb) QDs, without (with) ∼1 ML GaSb capping.…”

“…Advantages in this respect led to a number of different applications, such as active media in semiconductor lasers [1][2][3], as building blocks for quantum information devices, particularly for quantum repeaters [4][5][6], as efficient single and entangled photon sources [7][8][9][10][11][12][13][14][15], including highlyentangled states for quantum computing [16][17][18][19], or as nanomemories [20][21][22][23][24]. Among III-V QDs, particularly type-I indirect (InGa)(AsSb)/GaAs QDs embedded in a GaP(001) matrix [25,26] have recently attracted attention due to their promising use as storage units for the QD-Flash nanomemory cells [25,26], as potentially effective entangled photon sources [27], owing to their smaller fine-structure splitting (FSS) of the ground state exciton compared to well-known type-I systems such as (InGa)As/GaAs [13,14], and as quantum gates [27][28][29][30]. The concept of hole storage QD-Flash was ini-tially suggested by Bimberg and coworkers [20][21][22][23][24]31] following first pioneering studies [31] regarding the ...…”

“…The key feature of the QD-Flash is to combine the fast access times of Dynamic Random Access Memories (DRAM) with the non-volatility of the Flash, which leads to a universal memory type, potentially simplifying future computer architectures. Recently, type-I indirect (InGa)(AsSb)/GaAs/GaP QDs showed an improvement of one order of magnitude in the storage time compared to pure In 0.5 Ga 0.5 As/GaAs/GaP QDs [32,33], reaching ∼1 hr at room temperature [25,26]. This result represents to date the record for Metal-Organic Vapor Phase Epitaxy (MOVPE)-grown QDs, thus opening up the possibility to use this technique to fabricate memory devices based on high-quality III-V semiconductor QDs.…”

Dimension-Dependent Phenomenological Model of Excitonic Electric Dipole in InGaAs Quantum Dots

“…Due to their discrete energy levels with the molecular-like character [1] and strong quantum confinement of electrons and holes in all dimensions [2], semiconductor quantum dots (QDs) serve as an excellent solid-state platform for a number of appealing applications. Among others, they may be used as gain material for semiconductor lasers [3,4] or as building blocks of nonvolatile universal memory, so-called QD-Flash [5,6]. Due to near unity quantum efficiency and external-field tuneability, QD optical transitions are often used as sources of quantum light [7,8] in advanced quantum communication and computation schemes [9,10].…”