Zinc–Phosphorus Complex Working as an Atomic Valve for Colloidal Growth of Monodisperse Indium Phosphide Quantum Dots

Abstract

Growth of monodisperse indium phosphide (InP) quantum dots (QDs) represents a pressing demand in display applications, as size uniformity is related to color purity in display products. Here, we report the colloidal synthesis of InP QDs in the presence of Zn precursors in which size uniformity is markedly enhanced as compared to the case of InP QDs synthesized without Zn precursors. Nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and mass spectrometry analyses on aliquots taken during the synthesis allow us to monitor the appearance of metal− phosphorus complex intermediates in the growth of InP QDs. In the presence of zinc carboxylate, intermediate species containing Zn−P bonding appears. The Zn−P intermediate complex with P(SiMe 3 ) 3 exhibits lower reactivity than that of the In−P complex, which is corroborated by our prediction based on density functional theory and electrostatic potential charge analysis. The formation of a stable Zn−P intermediate complex results in lower reactivity, which enables slow growth of QDs and lowers the extreme reactivity of P(SiMe 3 ) 3 , hence monodisperse QDs. Insights from experimental and theoretical studies advance mechanistic understanding and control of nucleation and growth of InP QDs, which are key to the preparation of monodisperse InP-based QDs in meeting the demand of the display market.

Recombinant Escherichia coli as a biofactory for various single- and multi-element nanomaterials

“…These elements will require further studies to better understand the mechanisms that underlie the formation of NMs with respect to crystallinity and producibility. Formation of crystalline materials and transformation of amorphous to crystalline materials have been investigated for metal, metal oxide, and semiconducting NMs and also geologic and biologic minerals (26)(27)(28)(29); in some cases, kinetic and energetic factors were considered and explained. In this study, we employed the Pourbaix diagram analyses for predicting producibility and crystallinity of NMs from the thermodynamic aspect.…”

Mixed Mercaptocarboxylic Acid Shells Provide Stable Dispersions of InPZnS/ZnSe/ZnS Multishell Quantum Dots in Aqueous Media

“…Furthermore, particle sizes were also determined from the corresponding maxima of first exciton absorption. The first exciton absorption peak of the QDs was determined from the minimum of the second derivative of the absorption curve [47]. Combining the sizes obtained from HAADF-STEM images and exciton peaks, a calibration curve was obtained, as shown in Figure 3 (detailed data are shown in Table A4, Appendix E).…”

Towards the fluorescence retention and colloidal stability of InP quantum dots through surface treatment with zirconium propoxide

“…The inclusion of the harmful element Cd in such QDs, however, is a major obstacle to their application to commercial products. Therefore, various Cd-free compositions, such as III-V InP [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], I-III-VI CuInS 2 [17][18][19][20][21], and Pbbased halide perovskite [22][23][24], have been intensively explored for the synthesis of visible QD emitters. Among them, InP QDs are the leading visible emitters particularly with respect to PL QY, bandwidth, and nontoxicity.…”

“…In addition, the continuous synthetic advancement of InP QDs has led to a narrower emission bandwidth, which is directly associated with the size distribution of the cores. Through a slow growth process associated with the formation of a low-reactivity Zn-P complex in the synthesis of the In(Zn)P core, In(Zn)P QDs can possess a more uniform size distribution and consequently high color purity [11]. Moreover, the homogenous size distribution of smallsized InP cores can be maximally retained by adopting the successive ion layer adsorption and reaction method, resulting in green and red InP QDs with PL bandwidths of 36 and < 45 nm, respectively [12].…”