Monodispersed InP Quantum Dots Prepared by Colloidal Chemistry in a Noncoordinating Solvent

Abstract

III−V semiconductor quantum dots are of considerable interest as their applications cover a broad spectrum, from optoelectronic to biomedical technology. For them to be of practical value, there is a need for a method that provides rapid and scalable production of highly monodispersed nanoparticles. This paper reports an efficient and rapid method of producing highly monodispersed InP quantum dots using a novel precursor-based colloidal synthesis in a noncoordinating solvent. The method also allows judicious control over the size of the quantum dots and can also be extended to produce other III−V quantum dots. In this paper, the synthesis and characterization of highly monodispersed InP quantum dots from newly prepared indium(III) carboxylate complexes in octadecene are detailed. When using indium(III) carboxylate as the indium precursor, no surfactant or coordinating solvents are required to prepare high-quality InP quantum dots in octadecene. The in situ formation of a surfactant upon injection of the phosphine precursor [P(SiMe3)3] helps control the growth of the resulting quantum dots. Structural and optical studies (continuous wave and time-resolved) have been performed on the as-prepared InP quantum dots. In addition, time-resolved photoluminescence has been conducted on etched InP quantum dots. The effects of the carboxylate chain length in indium(III) carboxylate and injection temperature on the growth and properties of quantum dots have been studied.

Coreduction Colloidal Synthesis of III–V Nanocrystals: The Case of InP

“…[10,11] Their PL spectra contain two emission bands: one at the band edge and a second broader band at longer wavelengths (lower energies), showing the similar feature to those InP NCs prepared using the traditional TOPO method. [5,6,9,13] According to the previous investigations on the both bands, [5,6,9,13,23] the high-energy band is assigned to band-edge recombination and the low-energy band to recombination of surface states.…”

“…It is generally believed that such low PL efficiency is due to inadequate passivation of the NC surface. [5,9,11,13] Previous studies have shown that the PL efficiency of InP NCs could be drastically improved by photochemical etching of the NC surface with HF. [5,9,11,13] We thus treated our InP samples with a solution of HF through a modification of the standard method.…”

“…[5,9,11,13] Previous studies have shown that the PL efficiency of InP NCs could be drastically improved by photochemical etching of the NC surface with HF. [5,9,11,13] We thus treated our InP samples with a solution of HF through a modification of the standard method. [5,9,11,13] The comparative results of the PL properties for this typical sample before and after the etching are presented in Figure 3, showing that the HF-etching treatment can remove or passivate the surface states and produce high-efficiency band-edge emission.…”

Indium phosphide nanowires and their applications in optoelectronic devices

“…Hence, these were found to be potentially promising building blocks for the optoelectronic devices. Up until 2009, the SLS growth of InP NWs was primarily focused on the use of phosphines or organo-indium complexes containing one or more legating phosphines as precursors [70][71][72][73][74]. The most commonly used phosphine precursor was tris-trimethylsilylphosphine that is intrinsically highly toxic and pyrolytic that is detrimental to the process of scaling up preparation and subsequent mass production of InP NWs essential for economic device fabrication.…”

Effects of Curing Temperature on the Optical and Charge Trap Properties of InP Quantum Dot Thin Films

“…The presence of two peaks near 132.9 and 129.3 eV were very much similar to previous results reported for InP QDs. 16 It has been already reported by Guzelian that the peak near 129.3 eV is due to phosphorous from InP QDs, and that the peak near 132.9 eV is due mainly to oxidized phosphorous. 5(d) Figure 8(c) shows the high-resolution spectrum of In 3d region.…”