Synthesis and Characterization of Cadmium Phosphide Quantum Dots Emitting in the Visible Red to Near-Infrared

Abstract

The synthesis of high-quality cadmium phosphide quantum dots with emission wavelength maxima in the range from 1200 to approximately 760 nm are reported. The results demonstrate that the nucleation and growth linked with the optical properties can be controlled by the temperature, the growth time, and the addition of ligands such as oleylamine and trioctylphosphine. Photoelectrochemical investigations revealed that the cadmium phosphide QD-derivatized electrodes show an optical response and that photocurrents of several nanoamperes per square centimeter can be obtained upon illumination.

Pyramid-Shaped Wurtzite CdSe Nanocrystals with Inverted Polarity

“…6 Hot-injection is a versatile technique in the colloidal synthesis paradigm, as it provides a high degree of control over the NC size and shape distribution and over the nature of the stabilizing agent (ligand shell), as exemplified in case of the various transition metal chalcogenides 7-10 and pnictides. [11][12][13] In this regard, impurities play a major role in colloidal synthesis as they, 14 whether introduced accidentally or already present in the chemicals used, can lead to reproducibility issues, as illustrated for the role of tri-n-octylphosphine oxide (TOPO) in the growth of cadmium selenide NCs [15][16][17] and that of in-situ formed acetate ions for lead selenide NCs. [18][19] Halide ions are a source of impurities which has come under intense scrutiny very recently, as can be envisaged from the numerous literature reports describing their influence on the growth of NCs of various materials such as lead chalcogenides, 20-23 nickel sulfide, 24 copper sulfide, 24 and noble metals.…”

Synthesis of Cadmium Arsenide Quantum Dots Luminescent in the Infrared

“…Reports of the synthesis of II-V semiconductor nanocrystals have appeared previously, [19][20][21][22][23][24] but to our knowledge, the only report of the preparation of Cd 3 As 2 QDs used an aqueous method involving arsine gas that produced a solution with absorption and emission features in the visible and fluorescence quantum yields (QY) <5%. 23 Our approach was inspired by previous reports of the synthesis of Cd 3 P 2 QDs from cadmium(II) oleate and .…”

Room‐Temperature Synthesis of Air‐Stable and Size‐Tunable Luminescent ZnS‐Coated Cd3P2 Nanocrystals with High Quantum Yields

“…[3] Surprisingly little research on synthetic strategies has been performed, leading, until recently, to limited sized nanocrystals (NCs; 2 to 3 nm) and incomplete optical characterizations or poor properties. [4][5][6][7] In 2010, both Peng et al [8] and Hickey et al, [9] successfully obtained Cd 3 P 2 NCs of controllable sizes spanning the spectral range between 500 and 1500 nm. In both cases, the synthesis relies on the same system of reactants (CdO, oleic acid (OA) and tris(trimethylsilyl)phosphine ((TMS) 3 P) in the presence or not of additional surfactants (oleylamine and trioctylphosphine), in octadecene (ODE).…”

“…In both cases, the synthesis relies on the same system of reactants (CdO, oleic acid (OA) and tris(trimethylsilyl)phosphine ((TMS) 3 P) in the presence or not of additional surfactants (oleylamine and trioctylphosphine), in octadecene (ODE). High temperatures are required, either for the formation of the Cd 3 P 2 NCs (250 8C for Peng et al [8] ), or for the solubilization of the cadmium precursor (270 8C for Hickey et al [9] ). Nearly monodisperse, the obtained NCs present good quality optical properties with quantum yields (QYs) !…”

“…The photoluminescence (PL) quantum yield (QY) of 58 % is comparable with the highest QYs described in the literature for Cd 3 P 2 QDs prepared at high temperature. [8,9] Remarkably, the sizes of Cd 3 P 2 NCs can be finely controlled by varying the temperature of reaction and the concentrations of the reactants. Thus, their emission peaks positions can be tuned in the range 616-976 nm.…”