Ligand-Controlled Colloidal Synthesis and Electronic Structure Characterization of Cubic Iron Pyrite (FeS2) Nanocrystals
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- 作者：J. Matthew Lucas ; Chia-Chi Tuan ; Sebastien D. Lounis ; David K. Britt ; Ruimin Qiao ; Wanli Yang ; Alessandra Lanzara ; A. Paul Alivisatos
- 刊名：Chemistry of Materials
- 出版年：2013
- 出版时间：May 14, 2013
- 年：2013
- 卷：25
- 期：9
- 页码：1615-1620
- 全文大小：359K
- 年卷期：v.25,no.9(May 14, 2013)
- ISSN：1520-5002
文摘
Iron pyrite (FeS2) is a promising photovoltaic absorber because of its Earth abundance, high optical extinction, and infrared band gap (Eg = 0.95 eV), but its use has been hindered because of the difficulty of phase pure synthesis. Pyrite phase purity is a paramount concern, as other phases of iron sulfide have undesirable electronic properties. Here we report the synthesis of phase pure iron pyrite nanocrystals with cubic morphology and a mean dimension of 80 nm. Control over the nanocrystal shape was achieved using an unusual ligand, 1-hexadecanesulfonate. The particles were characterized via synchrotron X-ray spectroscopy, indicating an indirect band gap of 1.00 卤 0.11 eV and a valence bandwidth of nearly 1 eV. Transmission electron microscopy from early reaction stages suggests a nucleation and growth mechanism similar to solution precipitation syntheses typical of metal oxide nanocrystals, rather than the diffusion-limited growth process typical of hot-injection metal chalcogenide nanocrystal syntheses.