By-product processing of Si3N4 saw-tooth nanoribbons during carbon foam processing using pyrolysis–nitridation reactions. Issue 36 (31st August 2017)

• Record Type: Journal Article
• Authors: Farhan, Shameel; Wang, Rumin; Zhang, Dandan; Li, Kezhi
• Is Part Of: CrystEngComm. Volume 19:Issue 36(2017)
• Page Start: 5432
• Page End: 5441
• Publication Date: 2017-08-31
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c7ce01121k
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : A novel concept of by-product processing of high-yield Si3 N4 nanoribbons over the outer surface of carbon foams containing in situ grown silicon nanowires during high temperature carbonization treatment. Abstract : Si3 N4 saw-tooth nanoribbons (SNSNs) have been synthesized via a novel approach involving a by-product pyrolysis–nitridation process during carbon foam manufacturing at 1450 °C. The SNSNs formed are ribbon shaped, 80–750 nm wide, 70–80 nm thick and several micrometres in length. The process simply involved thermal pyrolysis of a powdered mixture containing carbon foam precursors and silicon powder under flowing high-purity nitrogen. Pyrolysis gases rich in silicon, silicon oxide and active nitrogen vapours promoted the subsequent synthesis of the SNSNs over the outer surface of the carbon foams via a vapour–solid mechanism. The crystal structure, morphology, chemical composition, growth mechanism and photoluminescence (PL) properties have been studied. The infrared adsorption of SNSNs exhibited two absorption bands with all the peaks related to the Si–N bonds of the α-Si3 N4 crystalline structure. X-ray photoelectron spectroscopy measurements further confirmed the chemical composition, with minor impurities such as oxygen and carbon. A single nanoribbon has the same width-to-thickness ratio, suggesting a stable morphology resulting from the reduction of the overall surface energy. Intense PL was observed centred at 2.03, 2.48, 2.62, and 3.01 eV, which resulted from the recombination between the intrinsic conduction band edges and silicon dangling bonds with deep-level or trap-level states.