Fourier Tansfrom Infrared Spectrometry UiO傅里葉變換紅外光譜 UIO

1、a fourier transforminfrared absorption study of hydrogen and deuteriumin hydrothermal zno-master presentation 14. jan 2009-hans bjrge normann-web: http:/folk.uio.no/hansno/filer/master_final_15des.pdfoutline1. backgroundzinc oxideinfrared radiationmolecular processesftir / spectrometry2. measurement

2、s3. hydrogen in zno4. isotopic substitution5. results6. conclusionftir - introduction study the interaction between infrared light and matter non destructiveapplications:identification of compounds in chemistrystudy impurities in semiconductorszinc oxidesemiconductor with eg=3.4 evhexagonal wurtzite

3、 type structureour sample dimensions = 10 x10 x0.5 mmsome zno applicationsoptical devicestransparent conductive oxide (tco)blue/uv light emitting diodes (leds)issuesohmic and schottky contactsp-type dopinggrowthimpurities and crystal defectsinfrared radiationwavenumber/wiki

4、pedia/en/8/8a/electromagnetic-spectrum.pngmolecular processes/wikipedia/en/8/8a/electromagnetic-spectrum.pnge-bond breaking and ionizationelectronic excitationvibrationrotationinfrared absorptionir absorption by defectsenergy is transferred into quantized vibrational excita

5、tions 2. measurements1. backgroundzinc oxideinfrared radiationmolecular processesftir / spectrometry2. measurements3. hydrogen in zno4. isotopic substitution5. results6. conclusionabsorption vs. wavenumberhow can we obtain an intensity scan for many wavenumbers?2 main methodsdispersion spectrometer

6、ftirdispersion spectrometer1. wavelength separation2. slit3. sample4. detectorv5. computeriftirthe michelson interferometer principle1. example: monochromatic light detectormovable mirrorstationary mirrorbeamsplitterinterference = optical path difference = (n + ) = n ftirdichromatic sourcevi- l -l/2

7、 0 l/2 limoveable mirrorftirbroadband sourcevcontinuous ir spectruminterferogram0iifourier transformtime domain: i vs. frequency domain: i vs. vftiviadvantages of ftirthroughput advantagecircular aperture, high signal intensity high signal to noise ratiomultiplex advantageall frequencies are measure

8、d at the same timeprecision advantageinternal laser control the scanner built in calibrationftir minalabbruker ifs 113v (genzel type interferometer)detection limit 1014 - 1015 cm-3ftir minalaboptical layoutsample holdermeasurementbackground spectrum = i0sample spectrum = ii0 ifourier transformed i v

9、s vabsorbancereflectivityabsorbance and beer-lambert lawd = sample thicknessc = absorbant concentration = absorption coefficient3. hydrogen in zno1. backgroundzinc oxideinfrared radiationmolecular processesftir / spectrometry2. measurements3. hydrogen in zno4. isotopic substitution5. results6. concl

10、usionhydrogen in znoo-h configurations?lio-h configurations?o-h stretch modes occurs always in the 3200 3600 cm1 regionshi et. al. physical review b, 73(8):81201, 2006li et. al. physical review b, 78(11), 2008.4 samplesv85 and v104untreated (as-grown) samplesheat treated at 400 oc for 70 hoursv91ion

11、 implanted with hydrogenheat treated at 400 oc for 70 hoursv92ion implanted with deuteriumheat treated at 400 oc for 70 hoursdepthlog concentration4. isotopic substitution1. backgroundzinc oxideinfrared radiationmolecular processesftir / spectrometry2. measurements3. hydrogen in zno4. isotopic subst

12、itution5. results6. conclusionisotopic substitution h and dharmonic oscillator approximationratio between o-h and o-d frequency = angular frequency, k = force constant, = reduced mass and m,m = masso-d modes expected at 2300 2600 cm15. results1. backgroundzinc oxideinfrared radiationmolecular proces

13、sesftir / spectrometry2. measurements3. hydrogen in zno4. isotopic substitution5. results6. conclusiondtgs-detector measurementsir parallel to c-axis of the crystalas-grown samplesion-implantation / simso-facezn-faceh-implantation: e = 1.1 mevd-implantation: e = 1.4 mevdose: 2 x 1016 cm-2 on both si

14、desinsb-detector measurementsir parallel to c-axisas-grown samplesannealedinsb-detector measurementsir parallel to c-axishydrogen implantedannealedpolishedinsb-detector measurementsir parallel to c-axisdeuterium implantedannealedpolishedinsb-detector measurementsir perpendicular to c-axisinsb-detect

15、or measurementsk perpendicular to c-axis measurementsas-grown and annealedinsb-detector measurementsk perpendicular to c-axis measurementshydrogen implanted and annealed / polishedinsb-detector measurementsk perpendicular to c-axis measurementsdeuterium implanted and annealed / polishedisotopic shif

16、tsisotopic shiftsquantification of the hydrogen content.integrated absorbance (ia)absorption strength per speciesd-dose: (1.46 0.54) x 1017 cm-2 ia (2644 peak): 0.233 cm -2 d = (1.72 0.63) x 10-18 cmquantification of the hydrogen content.similar treatment on hydrogen is not easya conversion factor i

17、s needed: d x c = h from other oxides c = 1.31 (linbo3), 1.88 (tio2)approximation czno 1.595 h = (2.74 1.01) x 10-18 cmintegrated absorbace of the 3577 cm-1 peaks h = (2.74 1.01) x 10-18 cmtotal h dose introduced: 4 x 1016 cm-2 total h dose already present (v85): (2.8 1.0) x 1016 cm-2 quantification

18、 of the hydrogen contentpossible defect identification2644 / 3577 cm-1 peaks are assigned a od-li /oh-li complexthe rest of the peaks?o-h configurations that may be related to vacanciessuggestions for future workimplantation of higher h-doseannealing timepolarizing filteruni-axial stress6. conclusio

19、neight vibrational modes excellent isotopic shifts!in addition, modes at 2613, 3279 and 3483 cm-1 we observe previously unreported o-d modes close associated with defects involving vacanciesabsorption strength per deuterium species has been determined absorption strength per hydrogen species has been approximatedo-h-li configuration supported by sims/ftirintro