27 KB647 KB22 KB200020242011Bitenc, MarkoCrnjak Orel, Zoricaštevilka:3letnik:45str. 287-292ISSN:1580-2949COBISSID:861354URN:URN:NBN:SI:doc-QZLC4KC4enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijecinkov oksidelektronska mikroskopijahidrocinkitprecipitacijasončne celiceHydrothermal growth of Zn5(OH)6(CO3)2 and its thermal transformation into porous ZnO film used for dye-sensitized solar cells| Hidrotermalna rast Zn5(OH)6(CO3)2 s termično transformacijo v porozno plast ZnO, uporabljeno za elektrokemijske sončne celice|Zinc oxide (ZnO) films, composed of nano-sheets, were prepared by the thermal decomposition of hydrozincite film precursor (Zn5(OH)6(CO3)2, ZnHC). The ZnO film kept the morphology on the microscale level during the heat treatment, while the thermal decomposition caused the formation of a nano-porous structure of the nano-sheets' surface. ZnHC precursor was hydrothermally synthesized on the conductive glass from zinc nitrate and urea. The influence of media (water or mixture of water/ethylene glycol), PVP-K additive and the concentration of the initial reagents, on the morphology of the film were observed. The growth and morphology of the ZnHC film was followed with FE-SEM microscopy and the formation mechanism of the ZnHC film, formed in the water, was proposed. The assumed growth mechanism follows the concept of a self-assembling mechanism of the nanometer-sized building units into nano-sheets of ZnHC with a thickness of "20 nm. These nano-sheets are further agglomerating into porous film. The thickness of the film was around (5, 8, 10 and 20) mum after (2, 3, 4 and 24) h of synthesis, respectively. The addition of PVP-K and ethylene glycol retards the growth of ZnHC film. Moreover, the addition of PVP-K affects the interactions between particles and the substrate, which enable the parallel growth of the nano-sheets on the substrate surface. As prepared ZnO films were used for DSSCs, where the conversion efficiency was "0.6 %Cinkov oksid (ZnO) smo pripravili kot tako plast na prevodni podlagi s termično obdelavo prekurzorja hidrocinkita (Zn5(OH)6(CO3)2, ZnHC). Tako pripravljena plast je bila sestavljena iz nanolističev, ki so po termični obdelavi obdržali svojo obliko na mikroskopskem nivoju, medtem ko so na njihovi površini nastale luknjice nanovelikosti. Plast ZnHC smo pripravili s hidrotermalno precipitacijo cinkovega nitrata s sečnino. Ob tem smo opazovali vpliv različnih koncentracij začetnih reagentov, medija (voda in mešanica vode/etilen glikola) in dodatkov (PVP-K) na rast in morfologijo nastalega produkta, ki smo ju spremljali z FE-SEM-mikroskopijo. Na osnovi rezultatov opazovanja vzorcev, pripravljenih v vodnem mediju, smo predpostavili mehanizem rasti plasti ZnHC. Ugotovili smo, da ta mehanizem sledi konceptu povezovanja nanogradnikov v večje urejene kristalne mikrostrukture z obliko nanolističev z debelino "20 nm. Nanolističi ZnHC se na podlagi aglomerirajo v porozno plast. Debelina plasti je bila približno 5 mim po 2 h, 8 mim po 3 h, 10 mim po 4 h in 20 mim po 24 h sinteze. Dodatek PVP-K in etilen glikol upočasnita rast plasti ZnHC. Poleg tega je dodatek PVP-K vplival na interakcijemed lističi in podlago, ki omogočijo rast lističev vzporedno s površino podlage. Plasti ZnO smo uporabili za izdelavo elektrokemijskih sončnih celic, katerih učinkovitost pretvorbe sončne energije v električno je "0,6 %TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije