ROOM TEMPERATURE PHOTOCHEMICAL STABILIZATION OF CATALYST THIN FILMS - PowerPoint PPT Presentation

ROOM TEMPERATURE PHOTOCHEMICAL STABILIZATION OF CATALYST THIN FILMS OF THE METASTABLE β -Bi2O3 PHASE M. Lourdes Calzada lcalzada@icmm.csic.es D.Perez-Mezcua, I.Bretos, R.Jiménez, J.Ricote, R.J.Jiménez-Rioboó, C.Gonçalves da Silva, & D.Chateigner, & L.Fuentes, * R.Sirera $ Inst. Ciencia de Materiales de Madrid (ICMM-CSIC). Cantoblanco, 28049. Madrid. Spain. & CRISMAT-ENISCAEN and IUT-Caen, Univ.Caen Normandie, 14050 – Caen. France. * Centro de Investigación en Materiales Avanzados, 31109 – Chihuahua. México. $ Departamento de Química, Facultad de Ciencias, Universidad de Navarra, E-31008 Pamplona, Navarra. Spain. Spring Mee*ng 2016 Lille – France Ins$tuto de Ciencia de Materiales de Madrid

Motivation & Background UV-irradiation Photochemical synthesis (low-temperature processing) and stabilization of non-equilibrium phases Ins$tuto de Ciencia de Materiales de Madrid

Motivation & Background Chemical Solu*on Deposi*on PhotoChemical Solu/on Deposi/on (PCSD) (CSD) CSD produces films with high Reduc$on of the crystalliza$on temperature Photosensi$ve degree of composi$onal control Photosensi$ve to integrate ferroelectrics in standard CMOS precursor solu$on precursor solu$on and large deposi$on areas at low (<500 0 C) http://www.icmm.csic.es/eosmad/ cost, which have made them the deposi'on, drying method of prepara$on of a wide UV excimer lamp range of oxide films for electronic (222 nm, 225 W/m 2 ) applica$ons Gel film Synthesis of precursor solu*on photoexcita'on, thermocouple pyrolysis, ozonolysis Deposi*on onto Chamber Gas a substrate probe for the film flux drop of spinning Photoac$vated solu$on gel film Removal of organic species pyrolysis, crystalliza'on Low-temperature IR lamp (250 W) Crystallisa*on crystallized (600-800 0 C) ferroelectric film Ins$tuto de Ciencia de Materiales de Madrid

Motivation & Background UV-irradia/on of photosensi/ve compounds Photoactive sol, Ph Photosensitive precursor solution ( ) photoactive species deposition, drying Gel film photoexcitation, pyrolysis, ozonolysis on enhanced decomposition of organics UV irradiation Photoactivated gel film IR heating fro rom m 300ºC pyrolysis, crystallization Low-temperature (from 450ºC) crystallization of Low-temperature crystallized ferroelectric films PZT ferroelectric film Calzada et al., Adv.Mater., 2004, 16, 1620 Ins$tuto de Ciencia de Materiales de Madrid

Solution synthesis of metal oxide precursors Charge transfer metal complexes Metal complexes in N N + Metal-alkoxide solution with high sol UV-absorption N-methyldiethanolamine (MDEA) N-methyldiethanolamine (MDEA) Martín-Arbella et.al., J.Mater.Chem. , 2011 , 21, 9051. d 10 d 0 d 10 Martín-Arbella et al., J.Mater.Chem . , 2011, 21, 9051 Photosensitive solution with photoactive species ( ) UV-absorber molecules Chemical structure of metal complexes allows charge transfer bands between MDEA ligands and metallic formed with metal cations with a center (LMCT, MLCT) when the system is UV irradiated d 0 or d 10 electronic configuration Ins$tuto de Ciencia de Materiales de Madrid

Solution synthesis of metal oxide precursors General applicability !!! Low temperature deposition challenging for any oxide film H He Possible solution synthesis of charge transfer metal Li Be B C N O F Ne complexes for most high-k dielectric oxides Na Al Si P Cl Ar Mg S Ca Sc Ti V Cr Fe Co Ni Cu Zn Ga Ge As Se Kr K K Mn Ge Br As Se Br Rb Sr Y Zr Nb Tc Ru Rh Pd Ag Cd Cd In Sn Sn Sb Sb Te Te Xe Rb Mo Ag I I Bi Po At Au Hg Tl Pb Cs Cs Ba La Hf Ta W Os Ir Pt Au Hg Tl Pb Bi Po Rn Re At Fr Ra Ac Rf Db Sg Hs Mt Bh Pm Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Bk Cf Es Fm No Lr Am Cm Md Ins$tuto de Ciencia de Materiales de Madrid

Bismuth (III) oxide precursors Func/onal bismuth oxides H He Bismuth is one of the less toxic heavy metal, which has increased the interest in bismuth containing materials. They show a wide variety of applications that include metallurgic Li Be B C N O F Ne additives, green catalysts, non-toxic pigments, biomaterials for biomedicine or cosmetics. Their compounds also show thermoelectric, ferroelectric and multiferroic properties. Na Al Si P Cl Ar Mg S Ca Sc Ti V Cr Fe Co Ni Cu Zn Ga Ge As Se Kr K K Mn Ge Br As Se Br Rb Sr Y Zr Nb Tc Ru Rh Pd Ag Cd Cd In Sn Sn Sb Sb Te Te Xe Rb Mo Ag I I Po At Au Hg Tl Pb Cs Cs Ba La Hf Ta W Os Ir Pt Au Hg Tl Pb Bi Po Rn Re At Fr Ra Ac Rf Db Sg Hs Mt Bh Pm Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Bk Cf Es Fm No Lr Am Cm Md Ins$tuto de Ciencia de Materiales de Madrid

Bismuth-based perovskite ferroelectric thin films BiFeO 3 and (Bi 0.5 Na 0.5 ) 0.945 Ba 0.055 TiO 3 perovskite films at low temperatures Perovskite oxide thin films deposited from UV-absorber precursor solutions and crystallized at low temperatures by UV-irradiation Pérez-Mezcua et al., J.Mater.Chem.C, 2014, 2, 8750 (Bi 0.5 Na 0.5 ) 0.945 Ba 0.055 TiO 3 film BiFeO 3 film 400º C 500 nm 500 nm Ins$tuto de Ciencia de Materiales de Madrid

Bismuth (III) binary oxide polymorphs Polymorphic forms of the binary oxides of bismuth (III) H He Possible solution synthesis of charge transfer metal Li Be B C N O F Ne complexes for most high-k dielectric oxides Na Al Si P Cl Ar Mg S Ca Sc Ti V Cr Fe Co Ni Cu Zn Ga Ge As Se Kr K K Mn Ge Br As Se Br Rb Sr Y Zr Nb Tc Ru Rh Pd Ag Cd Cd In Sn Sn Sb Sb Te Te Xe Rb Mo Ag I I Po At Au Hg Tl Pb Cs Cs Ba La Hf Ta W Os Ir Pt Au Hg Tl Pb Bi Po Rn Re At Fr Ra Ac Rf Db Sg Hs Mt Bh β -Bi -Bi 2 O 3 is the most active heterogeneous photocatalyst of these compounds and δ -Bi -Bi 2 O 3 Pm Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu has the highest oxide-ion conductivity of all of the binary Th Pa U Np Pu Bk Cf Es Fm No Lr Am Cm Md metal oxides M. Mehring. Coordination Chemistry Reviews. 2007, 251, 974. Ins$tuto de Ciencia de Materiales de Madrid

Bismuth (III) binary oxide polymorphs Stabiliza/on of δ -BiO 3 at room temperature ? δ− Bi 2 O 3 + 11) δ− (111) (1 + ++ δ− Bi 2 O 3 250ºC-350ºC 2) δ− (222) (22 + + Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 Al 2 O 3 ++ Bismuth oxide thin films deposited + Ø aluminium oxide substrate from UV-absorber precursor. The ++ Ø borosilicate glass substrate crystallization is accelerated by UV- ++ Ø silicon substrate irradiation and is independent from Pt 111 ++ the substrate Ø Pt-coated silicon substrate 20 30 40 50 60 70 Switzer et al., Science, 1999, 284, 293. 2 θ (º) Luca et al ., J.Appl.Phys. 2013, 113, 046101 Ins$tuto de Ciencia de Materiales de Madrid

Bismuth (III) binary oxide polymorphs Stabiliza/on of δ -BiO 3 or β -Bi 2 O 3 thin films at room temperature ? 0 .0 The conductivity of these films using planar capacitors shows -0 .5 a chaotic behavior similar to that measured in published -1 .0 - 1 )) Sl ope -2.98 - 1 cm works that report the stabilization of the non-equilibrium δ - -1 .5 ( Ω Bi 2 O 3 phase in films prepared by different methods. ( σ d . c . -2 .0 -2 .5 log Switzer et al., Science, 1999, 284, 293 Pt 3 50 K N 2 1 m v a .c. -3 .0 Skorodumova et.al., Appl.Phys.Lett. 2005, 86, 241910. . Lin e ar fit -3 .5 Koza et al., ACS Nano. 2013, 7(11), 9946 . 0 1 2 3 4 5 Log(time elapsed (s)) The conductivity behavior of the Bi 2 O 3 films, measured for the first time close to room temperature, indicates that the high-temperature β -Bi 2 O 3 polymorph is the phase stabilized in these films by the UV-irradiation. 1 δ These measurements heating 0 Ahrrenius fitting show an electrical -1 cooling Ahrrenius fitting log( σ d.c. Ω -1 cm -1 ) -2 behaviour of the films Conductividy data -3 similar to that measured β 1.27eV -4 α at high temperature for -5 1.27eV β -Bi 2 O 3 bulk ceramics extrapolated β -Bi 2 O 3 -6 conductvity to lower temperature -7 Harwig et al., J.Sol.Stat.Chem. -8 1978, 26, 265 0.9 1.2 1.5 1.8 2.1 1000/T(K) Ins$tuto de Ciencia de Materiales de Madrid