Synthesis of Highly Luminescent SnO2 Nanocrystals: Analysis of their Defect‐Related Photoluminescence Using Polyoxometalates as Quenchers. (30th November 2017)

• Record Type: Journal Article
• Authors: Pramata, Azzah Dyah; Suematsu, Koichi; Quitain, Armando Tibigin; Sasaki, Mitsuru; Kida, Tetsuya
• Is Part Of: Advanced functional materials. Volume 28:Number 4(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-11-30
• Subjects: nanocrystals -- photoluminescence -- polyoxometalates -- quenching -- tin dioxide; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201704620
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Colloidal semiconductor nanocrystals (NCs), called quantum dots (QDs), have been intensively studied because of their excellent photoluminescence (PL) quantum yields. However, commercial QDs such as CdSe and InP contain toxic or expensive rare elements, limiting their sustainable use. This study focuses on nontoxic, stable, and cheap tin oxides, and synthesized luminescent SnO2 NCs of ≈2 nm in size by a heating‐up method. Tin precursors and diols in a high‐boiling point solvent with oleylamine as the surfactant are heated at 240 °C. SnO2 NCs show defect‐related photoluminescence at 400–460 nm by excitation at 370 nm, achieving a high quantum yield of more than 60%. The PL intensity is stable even when the NCs are stored in atmospheric air at room temperature for over 1 year. The defect‐related emissions of the SnO2 NCs are studied using polyoxometalates (POMs) as the PL quencher. POMs efficiently quench the PL emissions by extracting excited electrons from the conduction band and shallow surface defects. The results reveal that PL emissions from SnO2 NCs are associated with radiative charge recombination via shallow defect levels on the surface and in the bulk, demonstrating the effectiveness of the PL quenching technique using POMs in studying the PL emission mechanism in QDs. Abstract : This study is carried out with a particular emphasis on the photoluminescence (PL) emission mechanism of SnO2 nanocrystals (NCs) . A one‐pot synthetic route is developed for SnO2 NCs with controllable sizes, tunable bandgaps, and a high quantum yield. A PL quenching technique is employed to study the defect‐related PL emission from the SnO2 NCs using polyoxometalates as quenchers.