UV sensitivity enhancement in Fe-doped ZnO films grown by ultrafast spray pyrolysis

• Published in: Optical materials 2021-02, Vol.112, p.110768, Article 110768
• Main Authors: Nurfani, E., Lailani, A., Kesuma, W.A.P., Anrokhi, M.S., Kadja, G.T.M., Rozana, M.
• Format: Article
• Language: English
• Subjects: Fe doping; Spray pyrolysis; UV photodetectors; ZnO film
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2020.110768

The effect of Fe dopant on structural and photosensitivity properties of ZnO thin films have been studied. The Fe-doped ZnO films were fabricated by ultrafast spray pyrolysis for 30 s. As a result, X-ray diffraction analysis demonstrates that the deposited films are polycrystalline with the hexagonal wurtzite structure. Fe doping in the ZnO system provokes not only the decrease of crystallinity and crystallite size (~50% for Fe concentration of 0.5%) but also the increase of interplanar spacing and strain. Surface morphology images show that the grain size of 3% Fe-doped ZnO (67 nm) is smaller than that of the pure ZnO (114 nm). Based on I–V characterizations, Fe doping increases photocurrent as well as UV sensitivity up to 21 times (1.5% Fe) and 70 times (3% Fe) than that of the undoped ZnO. This study is important to improve the functionality of ZnO as a UV photodetector. •ZnO thin films are fabricated using ultrafast spray pyrolysis for 30 s.•Fe doping decreases the crystallinity and crystallite size of ZnO.•Fe concentration of 3% has the highest UV sensitivity.•Lower dark current and higher photocurrent are found in Fe concentration of 3%.