Effects of background gases and pressure in pulsed laser deposition of Al-doped ZnO
Document Type
Article
Publication Date
5-1-2020
Abstract
Background gases (O-2, He or Ar) with the pressure from similar to 10(-3) Pa to 133.3 Pa are used in 355 nm laser deposition of Al-doped ZnO at room temperature. The effects of these gases and pressure on plasma formation are studied by optical emission spectroscopy (OES) and time of flight (TOF) measurement. The OES results show that the emission intensity of the species in O-2 and Ar decrease slightly and then increase exponentially above similar to 5 Pa. The emission intensity in Ar is the highest, followed by emission in O-2 whilst the emission in He is low and weakly depend on background gas pressure. TOF measurements indicate that the ion velocity decrease with increasing O-2 and Ar pressure at about 5-10 Pa. The ion velocity is highest in He while the ion velocities in O-2 and Ar are similar. Thin-film samples deposited in different gas at 2.6 Pa are amorphous, but those deposited at 133.3 Pa are crystalline and exhibit different morphologies and optical properties depending on type of gas. Samples deposited in O-2 are highly transparent but those deposited in He and Ar contain nano and micron-sized structures with <50% transmittance. In addition, Zn crystallites are detected by X-ray diffraction.
Keywords
Pulsed laser deposition, Laser produced plasma, Background gases, Pressure, Aluminum-doped zinc oxide, Nanostructured films
Divisions
Science,PHYSICS
Publication Title
Thin Solid Films
Volume
701
Publisher
Elsevier
Publisher Location
PO BOX 564, 1001 LAUSANNE, SWITZERLAND