Structural, Morphological, and Electrical Properties of Zinc Oxide Thin Films Grown by Pulsed Laser Deposition

Zinc oxide (ZnO) thin films are known for their remarkable optical and electrical properties, m-aking them highly suitable for a wide range of applications in electronics, optoelectronics, and sensing devices (detectors). The current research carried out a detailed study on the deposition and characterization of zinc oxide thin films using the pulsed laser deposition (PLD) technique on two different substrates: silicon (p‑type) and glass (amorphous). Depositions were carried out at a base pressure of $$8 \times {{10}^{{ - 6}}}$$ mbar in a vacuum, and in an oxygen environment at a pressure of $$1.5 \times {{10}^{{ - 1}}}$$ mbar. A solid ZnO target was ablated using the third harmonics (355 nm) of a Q-switched Nd:YAG laser operated at a laser pulse energy of 38 mJ with a corresponding laser fluence of 47 J/cm2. Substrate temperature was maintained at 500°C for a deposition time of 40 min. The structural, morphological, optical, and electrical properties of the thin films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and the four-probe method. The thin film grown in an oxygen environment on the silicon substrate shows the best crystalline structure, while both thin films grown in a vacuum exhibit an amorphous nature. Electrical characterization performed using the four-probe method revealed a decrease in resistivity with increasing temperature for all deposited films; however, the thin film grown on a glass substrate in an oxygen atmosphere exhibited comparatively higher resistivity.