INFLUENȚA DOPĂRII CU ALUMINIU ASUPRA PROPRIETĂȚILOR OPTICE ALE STRATURILOR SUBȚIRI DE ZnO

Ion LUNGU

Abstract


Straturile nanostructurate ZnO au fost sintetizate din soluții chimice prin metoda pirolizei pulverizate. Prin analiza difracției cu raze X (XRD) și a spectroscopiei UV-Vis au fost studiate efectele variației concentrației de aluminiu asupra proprietăților optice ale straturilor nanostructurate de ZnO. Concentrația aluminiului în soluția inițială a fost fixată la 0, 1, 2, 3 și 5%. Analiza difracției cu raze X (XRD) confirmă că doparea cu 1% de aluminiu, în comparație cu celelalte concentrații, îmbunătățește structura cristalină. Cu creșterea concentrației de aluminiu dimensiunea cristalitelor se mic­șorează. Studiul spectroscopiei UV-Vis a straturilor subțiri indică o transmitanță sporită (~90%) în regiunea vizibilă a spectrului energetic cu lărgimea benzii interzise de 3,23 eV pentru ZnO nedopat și de 3,32 eV pentru ZnO dopat cu Al, care este aproape de valoarea „bulk” a ZnO (3,36 eV).

 

THE INFLUENCE OF THE DOPING WITH ALUMINUM ON THE
OPTICAL PROPERTIES OF ZnO THIN FILMS

ZnO nanostructured layers were synthesized from chemical solutions by the spray pyrolysis method. By using X-ray diffraction (XRD) method and UV-Vis spectroscopy, the effects of varying aluminium concentration on the optical properties of ZnO nanostructured layers were studied. The concentration of aluminium was set at 0, 1, 2, 3 and 5% in the initial solution. X-ray diffraction (XRD) analysis confirms that doping with 1% aluminium, compared to other concentrations, improves the crystal structure. As the concentration of Al increases, the size of the crystallites decreases. The study of UV-Vis spectroscopy of thin layers indicates an increased transmittance (~ 90%) in the visible region of the energy spectrum with a bandwidth of 3.23 eV for undoped ZnO and 3.32 eV for Al-doped ZnO, which is close to the “bulk” value of ZnO (3.36 eV).


Keywords


ZnO, transmittance, reflectance, absorbance, spray pyrolysis, doped.

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References


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