Određivanje energije zabranjene zone Taucovom metodom

undergraduate thesis

• Title (english): The determination of band gap using Tauc method
• Author: Marija Tkalčević
• Mentor: Stanislav Kurajica (mentor)
• Committee member: Juraj Šipušić (predsjednik povjerenstva)
• Committee member: Stanislav Kurajica (član povjerenstva)
• Committee member: Vladimir Dananić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2016-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

U radu je predstavljena metoda određivanja zabranjene zone poluvodiča korištenjem UV-Vis difuzne refleksijske spektroskopije. Detaljno je opisana sama tehnika difuzne refleksijske spektroskopije, postupak transformacije difuzijskog refleksijskog spektra u Kubelka-Munk funkciju kao i konstrukcija Taucova grafičkog prikaza, odnosno određivanje zabranjene zone. Uzorci TiO2, ZnO te ZrO2 prvo su podvrgnuti rendgenskoj difrakcijskoj analizi kako bi se dobio uvid u njihov fazni sastav, odnosno čistoću. Utvrđeno je da su tri uzorka monofazna te se sastoje od anatasa, rutila i cinkita dok je četvrti uzorak smjesa monoklinskog i kubičnog ZrO2. Monofazni uzorci dalje su analizirani metodom UV-Vis difuzne refleksijske spektroskopije. Dobiveni spektri su transformirani u Kubelka-Munk funkciju te su konstruirani grafički prikazi ovisnosti Kubelka-Munk funkcije o energiji. Potom su konstruirani Taucovi grafički prikazi i iz njih su određene zabranjene zone anatasa, rutila i cinkita. Dobivene su zabranjene zone od 3,22 eV za anatas, 3,17 eV za rutil i 3,28 eV za cinkit. Dobive vrijednosti za energiju zabranjene zone uspoređene su s literaturnim vrijednostima.

Abstract (english)

The method for the determination of semiconductor band gap using UV-Vis diffuse reflectance spectroscopy has been presented. Diffuse reflectance spectroscopy technique, the transformation procedure of diffuse reflectance spectra to Kubelka-Munk function and construction of Tauc's plot, i.e. the determination of band gap, have been described in details. The samples of TiO2, ZnO and ZrO2 have been first subjected to X-ray diffraction analysis in order to gain insight in their phase composition, i.e. phase purity. It has been determined that three samples are monophasic and composed of anatase, rutile and zincite while fourth sample is mixture of monoclinic and cubic zirconia. Monophasic samples were further analyzed using UV-Vis diffuse reflectance spectroscopy. Obtained spectra were transformed to Kubelka-Munk function and the dependences of Kubelka-Munk functions on energy have been graphically displayed. Subsequently Tauc's plots have been constructed and using them band-gaps of anatase, rutile and zincite have been determined. Band gaps of od 3.22 eV, 3.17 eV and 3.28 have been obtained for anatase, rutile and zincite, respectively. The obtained band gaps were compared with literature data.

• Keywords: poluvodič; difuzna refleksijska spektroskopija; zabranjena zona; Kubelka-Munk funkcija; Taucov grafički prikaz
• Keywords (english): semiconductor; diffuse reflectance spectroscopy; band gap; Kubelka-Munk funkction; Tauc's plot
• Language: croatian
• URN:NBN: urn:nbn:hr:149:442781
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-02-02 12:17:19