title: Tunable near-infrared and visible-light transmittance in nanocrystal-in-glass composites.
abstract: Amorphous metal oxides are useful in optical, electronic and electrochemical devices. The bonding arrangement within these glasses largely determines their properties, yet it remains a challenge to manipulate their structures in a controlled manner. Recently, we developed synthetic protocols for incorporating nanocrystals that are covalently bonded into amorphous materials. This 'nanocrystal-in-glass' approach not only combines two functional components in one material, but also the covalent link enables us to manipulate the glass structure to change its properties. Here we illustrate the power of this approach by introducing tin-doped indium oxide nanocrystals into niobium oxide glass (NbOx), and realize a new amorphous structure as a consequence of linking it to the nanocrystals. The resulting material demonstrates a previously unrealized optical switching behaviour that will enable the dynamic control of solar radiation transmittance through windows. These transparent films can block near-infrared and visible light selectively and independently by varying the applied electrochemical voltage over a range of 2.5 volts. We also show that the reconstructed NbOx glass has superior properties-its optical contrast is enhanced fivefold and it has excellent electrochemical stability, with 96 per cent of charge capacity retained after 2,000 cycles.
authors: The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors: Anna
authors: A
authors: Llordés
authors: Guillermo
authors: G
authors: Garcia
authors: Jaume
authors: J
authors: Gazquez
authors: Delia J
authors: DJ
authors: Milliron
references: Nature. 2012 Sep 6;489(7414):128-32
references: 22955624
references: Science. 1985 Feb 22;227(4689):849-56
references: 17821215
references: Phys Rev Lett. 2007 Jun 1;98(22):225901
references: 17677860
references: Angew Chem Int Ed Engl. 2010 Apr 6;49(16):2878-82
references: 20301153
references: Nature. 2004 Nov 25;432(7016):488-92
references: 15565150
references: J Am Chem Soc. 2011 Feb 2;133(4):998-1006
references: 21175183
references: Nano Lett. 2012 Jul 11;12(7):3872-7
references: 22725257
references: Nature. 2004 Aug 12;430(7001):761-4
references: 15306804
references: Angew Chem Int Ed Engl. 2008;47(26):4844-6
references: 18496828
references: Nano Lett. 2011 Oct 12;11(10):4415-20
references: 21859093
references: Angew Chem Int Ed Engl. 2005 Jan 21;44(5):797-802
references: 15612076
references: Adv Mater. 2012 Jan 3;24(1):99-103
references: 22144334
references: Angew Chem Int Ed Engl. 2012 Jan 16;51(3):684-9
references: 22147424
references: J Am Chem Soc. 2007 Nov 14;129(45):13894-904
references: 17941637