Surface‐interface investigations of an ultrathin pulsed laser deposited NiO/ZnO bilayer structure

Abstract

We hereby report detailed structural and morphological studies for an ultrathin NiO/ZnO bilayer structure grown on sapphire (001) substrate using pulsed laser deposition technique. The combined X‐ray reflectivity (XRR) and grazing incidence X‐ray fluorescence (GIXRF) studies revealed formation of a low‐density defective ZnO interfacial layer of thickness ~32 Å at the ZnO/sapphire interface prior to growth of main ZnO layer. Our results further indicate that the variation of electron density across the NiO/ZnO bilayer structure is smooth and we do not observe presence of any interface layer between them. X‐ray diffraction measurements show that deposited ZnO layer is epitaxial in nature whereas NiO is highly oriented along (100) direction. The angle dependent X‐ray absorption near edge fine structure (XANES) measurements at Ni–K edge has been utilized to determine depth‐resolved oxidation state of Ni and the results have been correlated with the depth‐resolved electron density of NiO layer. The method described here offers nondestructive determination of the microstructural parameters as well as depth‐resolved mapping of oxidation state of a thin film‐based heterojunction device. It extends several advantages over destructive methods which are abundantly reported in literature.

Determination of the interface band alignment of Mg2Si/4H‐SiC heterojuction for potential photodetector application

“…The band alignment (Figure 5) reveals that the Mg 2 Si/4H‐SiC heterojunction could be a promising candidate for the construction of photodetector. For the photodetector, 29–31 first, a low leakage current is one of the requirements. The Mg 2 Si/4H‐SiC heterostructure could offer a proper barrier height (1.00 eV) for electrons and 1.47 eV for holes, which can decrease effectively the leakage current.…”

Dual effect to improve the electrical properties of SZO films grown by nitrogen pneumatic spray pyrolysis

“…Besides, it can be obtained in different forms: bulk materials, thick films, thin films, nanowires, nanotubes, etc. Numerous techniques can be used to elaborate high‐quality ZnO films such as: sputtering (Xu & Wang, 2020), chemical vapor deposition (Ehsan et al, 2022), sol–gel (Parashar et al, 2020), hydrothermal method (Ameen et al, 2012; Yang et al, 2009; Ye et al, 2010), SILAR technique (Shishiyanu et al, 2005), thermal evaporation method (Navale & Mulla, 2009; Zhou et al, 2013), pulsed laser deposition (PLD) (Trivedi et al, 2020), and spray pyrolysis (Maldonado et al, 1999; Paraguay et al, 2000). Compared to other techniques, the spray pyrolysis method presents some advantages such as: simplicity, low cost, reproducibility, and the possibility of producing large surface films (Dallaev et al, 2019; Ramazanov et al, 2014).…”