Structure and band gap tunable CuInS2 nanocrystal synthesized by hot-injection method with altering the dose of oleylamine. (5th July 2018)

• Record Type: Journal Article
• Authors: Liu, Liwang; Li, Hong; Liu, Zirui; Xie, Ya-Hong
• Is Part Of: Materials & design. Volume 149(2018)
• Page Start: 145
• Page End: 152
• Publication Date: 2018-07-05
• Subjects: CuInS2 nanocrystal -- Tunable -- Structure -- Band gap -- Optical properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.04.015
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: By hot-injection method with altering the dose of oleylamine (OAm) in a reaction system, CuInS2 (CIS) nanocrystal with tunable structure and band gap is synthesized. Through various measurements, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), it is demonstrated experimentally that when the dose of OAm is relatively high (2.0 and 2.5 ml in this work), the combination phase of pseudo-chalcopyrite/wurtzite are obtained with a surprising existence of nanotwins. Besides, the molar fraction of wurtzite is larger in the sample using 2.5 ml OAm in the reaction system. However, when the dose of OAm becomes low, (0, 1.0 and 1.5 ml), pure zinc-blende CIS pyramidal quantum dots (QDs) can be prepared. This indicates that oleylamine promotes the formation of wurtzite structure. In addition, the band gap is larger with increasing of OAm, following the quantum refinement effects. This work serves as a facile method of synthesizing CIS nanocrystal with tunable structure and band gap, which will be possibly applied in the fabrication of their optoelectronic devices. Graphical abstract: Unlabelled Image Highlights: Using oleylamine (OAm) as a coligand to change the size, structure and bandgap of the CuInS2 (CIS) nanocrystals The formation of an intermediate phase, pseudo-chalcopyrite was observed and discussed in detail. Nanotwinned wurtzite structure of CuInS2 (CIS) was formed when the dose of oleylamine (OAm) is relativity high.