Preparation of Ultrafine Chalcopyrite Nanoparticles via the Photochemical Decomposition of Molecular Single-Source Precursors

Abstract

The synthesis and characterization of ultrafine CuInS2 nanoparticles are described. Ultraviolet irradiation was used to decompose a molecular single source precursor, yielding organic soluble approximately 2 nm sized nanoparticles with a narrow size distribution. UV-vis absorption, 1H and 31P{1H} NMR, and fluorescence spectroscopies and mass spectrometry were used to characterize decomposition of the precursors and nanoparticle formation. The nanoparticles were characterized by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy energy dispersive X-ray spectroscopy, powder X-ray diffraction (XRD), electron diffraction, inductively coupled plasma analysis, UV-vis absorption spectroscopy, and fluorescence spectroscopy. They have a wurzite-type crystal structure with a copper-rich composition. The hypsochromic shift in their emission band due to quantum confinement effects is consistent with the size of the nanocrystals indicated in the HRTEM and XRD analyses.

Synthesis of Chalcopyrite Nanoparticles via Thermal Decomposition of Metal-Thiolate

“…The stokes-shifts in the PL spectrum from the band gap ((a) 2.45, (b) 2.25 and (c) 2.04 eV) are about 0.3 eV. Such Stokes shift and its wide full width at half maximums (FWHM) of PL resemble the reported results, 13,14) indicating that ambient temperature PL is not attributed to the exciton recombination. …”

“…This is consistent with our experimental results. Comparing with aliphatic phosphine, 13) DT is a suitable capping agent for CuInS 2 NPs because the Cu to In ratio of CuInS 2 NPs derived from Cu-In thiolate is closer to the stoichiometry. Figure 4 shows UV-vis and PL spectra of CuInS 2 NCs obtained at various preparation temperatures, (a) 473, (b) 503 and (c) 533 K. In Fig.…”

“…14) In particular, chalcopyrite NPs with the quantum yield of about 5% were successfully synthesized via the thermal decomposition of single source precursors. 13,14) However, this method has several disadvantages: it is sensitive to atmospheric conditions, needs expensive starting reagents and the methodology becomes cumbersome. In this paper, we present a moderate and facile synthesis route of CuInS 2 NPs via thermal decomposition of Cu-In-thiolate at 473 K without using toxic raw materials.…”

Textural Evidence of Episodic Introduction of Metallic Nanoparticles into Bonanza Epithermal Ores

“…Bacteria-mediated ZnS formation has also been documented, and sphalerite formed by this process commonly occurs as self-organized spheroidal particles that are ~100 nm in diameter, which in turn composed of smaller aggregated nanoparticles of ZnS [38][39][40][41]. Chalcopyrite nanoparticles are routinely synthesized for their use in "nano" technological applications [42] and amorphous biogenic Cu(Fe)-S nanoparticles have also been documented by Saunders et al [41] forming in groundwater under sulfate-reducing conditions. No doubt other base-metal sulfide nanoparticles also form in black smoker settings along with FeS nanoparticles.…”

A new green synthesis method of CuInS2 and CuInSe2 nanoparticles and their integration into thin films

“…Peak broadening due to instrumental artefacts and strain are not considered here. The size of the crystallites d c has been determined using the Scherrer equation (Castro et al 2004;Gurin 1998;Nairn et al 2006;Bensebaa et al 2004) d c ¼ 0:9 k=b cos h where b (in radians) is the linewidth at an angle 2h (in radians) and k is the X-ray wavelength, 1.5406 Å . Based on the linewidth of the (112) diffraction peak, we estimate the size of the crystallite to be around 2.2 nm.…”