Fabrication of GaAs, In_xGa_1–xAs and Their ZnSe Core/Shell Colloidal Quantum Dots

Abstract

We first report the GaAs/ZnSe and InGaAs/ZnSe core/shell structured colloidal quantum dots (CQDs). GaAs based CQD, which are hard to obtain by the chemical synthetic method, can be prepared successfully using the acetylacetonate complex of indium and gallium as cationic precursors. We control the indium contents, and the photoluminescence emission is tuned from orange to deep red. InGaAs/ZnSe core/shell QDs show the best quantum yield of 25.6%. A ZnSe outer shell protects the core and improves quantum yield, and it shows a large red shift owing to the quasi-type-I band structure.

Ag2ZnSnS4–ZnS core–shell colloidal quantum dots: a near-infrared luminescent material based on environmentally friendly elements

“…Consequently, there is an increased effort towards the development of heavy metal-free RoHS compliant low-cost luminescence phosphors as an alternative. 6 As a result indium/gallium based III-V group QDs such as InAs, InSb, GaAs [7][8][9][10] and I-III-VI group QDs such as CuIn(S/Se) 2 , AgIn(Se/ Te) 2 [11][12][13][14] with NIR emission have attracted significant interest.…”

“…Core-shell heterostructures of various binary and ternary QDs that emit NIR PL have been studied in the previous literature. 6,9,10,12 However, core-shell heterostructures of quaternary QDs have rarely been explored 27,28 due to synthetic impediments. Herein, we present the thiol free synthesis of bright tunable NIR luminescent AZTS-ZnS core-shell QDs with controlled growth of shell thickness.…”

Synthesis of NIR‐Emitting InAs‐Based Core/Shell Quantum Dots with the Use of Tripyrazolylarsane as Arsenic Precursor

“…In recent years group III–V semiconductor materials gained tremendous attention as less toxic surrogates for group II–VI nanomaterials in optoelectronic devices . Thereby, InAs QDs are one of the most promising candidates for near infrared (NIR) and short‐wave infrared applications, such as bioimaging, photovoltaics, photodetectors, and lasers .…”

Understanding and Curing Structural Defects in Colloidal GaAs Nanocrystals

“…16,20,22 Very recently, Park et al reported the formation of ∼1.8 nm GaAs NCs which, upon growth of a ZnSe shell, showed a weak band edge emission. 23 However, since the GaAs core was grown in the presence of a 3-fold excess of Zn precursor, the possibility of Zn intercalation into the lattice and subsequent alloy formation could not be neglected.…”

“…The short-lived nature of the bleach suggests fast trapping of electrons, which should be addressable by proper passivation of surface dangling bonds, e.g., by growing a wide band gap shell (ZnSe). 23 A serious limitation of this approach is that film-annealed GaAs NCs cannot be redispersed and used as colloidal solutions.…”