Effect of Substrate Temperatures on Structural and Optical Properties of ZnO Thin Films Produced by Ultrasonic Spray Pyrolysis

Abstract

In this study, ZnO thin films were deposited at three different temperatures of 350, 400, and 450 °C by the ultrasonic spray pyrolysis method. Zinc acetate dihydrate (Zn(CH₃COO)₂.2H₂O) was used as a zinc source in the production of ZnO thin film. XRD analysis confirmed that the ZnO thin films are in nano-sized hexagonal structure and the dominant peak position belongs the plane of (100). The crystal grain size was calculated using the Debye-Scherrer formula and found between 324.7-442.3 Å. When SEM surface images are examined, it is seen that ZnO thin films have a homogeneous structure and thicknesses vary between ~253-286 nm from SEM cross-section. The surface roughness of the films was examined with AFM, and the surface roughness values were obtained in the range of 23.00-43.44 nm. From the UV spectra of ZnO thin films, optical transmittance was found to be over 80%, and the forbidden bandgap energies in-between 3.13-3.26 eV.

Keywords

• Ultrasonic spray pyrolysis
• ZnO
• Surface morphology
• Substrate temperature
• Optical properties

Ultrasonik Sprey Piroliz ile Üretilen ZnO İnce Filmlerin Alttaş Sıcaklıklarının Yapısal ve Optik Özelliklerine Etkisi

Abstract

Bu çalışmada, ZnO ince filmler; 350, 400 ve 450 °C üç farklı sıcaklıktaki alttaşa ultrasonik sprey piroliz yöntemi ile biriktirilmiştir. ZnO ince film üretiminde çinko kaynağı olarak çinko asetat dihidrat (Zn(CH₃COO)₂.2H₂O) kullanılmıştır. Yapılan XRD analizleri, ZnO ince filmlerin, nano boyutta hekzagonal yapıda ve baskın pik pozisyonunun (100) düzleminde olduğunu doğrulamıştır. Kristal tane boyutu Debye-Scherrer formülü kullanılarak hesaplanmış ve 324.7-442.3 Å aralığında bulunmuştur. SEM yüzey görüntüleri incelendiğinde ZnO ince filmlerin homojen bir şekilde kaplandığı ve SEM kesit görüntülerinden kalınlıkların ~251-286 nm aralığında değiştiği görülmektedir. Filmlerin yüzey pürüzlülüğü AFM ile incelenmiş ve yüzey pürüzlülük değerleri 23.00-43.44 nm aralığında elde edilmiştir. ZnO ince filmlerin UV spektrumlarından, optik geçirgenlikleri %80' in üzerinde bulunurken, yasak enerji aralıkları 3.13-3.26 eV olarak bulunmuştur.

Keywords

• Ultrasonik sprey piroliz
• ZnO
• Yüzey morfolojisi
• Alttaş sıcaklığı
• Optik özellikler

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