Doping and thickness variation influence on the structural and sensing properties of NiO film prepared by RF-magnetron sputtering

Abstract

The NiO and NiO-Cu doped films with various Cu contents of 5.68, 10.34, and 14.64 at%. Were deposited on a glass substrate with various thickness 50, 100, and 150 nm by RF-reactive magnetron sputtering technique. The effect of the thickness and the doping on the structural, electrical, and sensory properties of the films was mainly investigated. The X-ray diffraction studies revealed that all the deposited films were of single crystalline nature and exhibited cubic structure with preferential growth along 200 and only NiO peaks appear in the NiO-Cu films and when the thickness increased from 50 to 150 nm, the grain size increases from 24.38 to 25.036 nm. Compositional analysis indicated that Cu content increased in the film as the bonded chips increase in the target surface. The electrical resistivity of the NiO film showed a high electrical resistivity 280 K X detected by a four point probe measurement and when the Cu content in the films is 5.68 at%. The q value is reduced significantly to 45.9 K X as Cu content is increased to 10.34 at%, and it further decreases to 25.3 K X when the Cu content further increases to 14.64 at% the resistivity value decrease to 10.45 K X. The Hall measurement for all NiO and Cu-doped NiO films shows p-type conduction and reduction in the mobility of charge carrier from 9.67 9 10 2 to 8.46 9 10 cm 2 /V s, when the concentrations of the charge carriers increase from 4.30 9 10 10 to 4.23 9 10 13 cm -3 . The sensory measurements for NiO and Cu-doped NiO films, show that the 50 nm thickness has the highest sensitivity and response time for the NO 2 gas at the operating temperature 150°C.

An effective H2S sensor based on SnO2 nanowires decorated with NiO nanoparticles by electron beam evaporation

“…49 The carrier density and hole mobility of NiO are 4.30 Â 10 10 cm 3 and 9.67 Â 10 2 cm 2 V À1 s À1 , respectively. 51 The conductivity of NiO is much lower than that of NiS. Therefore, when exposed to H 2 S gas, suldation of NiO to NiS reduced the sensor resistance.…”

Study of structural and morphological properties of RF-sputtered SnO2 thin films and their effect on gas-sensing phenomenon

“…Deshwal and Arora [23] studied the sensing response for acetone gas by optimizing the thickness of ZnO thin films and reported a sensing response of 63.3 measured at 320°C for an optimized thickness of 410 nm for a ZnO-sensing layer. Hassan et al [24] deposited 50nm-, 100-nm-, and 150-nm-thin NiO-and NiO-Cudoped films by radiofrequency (RF) magnetron sputtering technique. It was reported that 50-nm-thick NiO-and NiO-Cu-doped thin films gave the highest sensitivity toward NO 2 gas.…”

Inductive Effect of Nd for Ni3+ Stabilization in NdNiO3 Synthesized by Reactive DC Cosputtering

“…Among the nickel oxide family, the simplest compound is NiO. This oxide must fulfill and integrate a wide range of applications as antiferromagnetic layers, − p -type transparent conducting films in electrochromic devices, − photocatalytic layers, or functional sensor layers for chemical sensors. − These different fields are allowed by the combination of its excellent chemical stability and its very interesting electrical, optical and magnetic properties. In addition, NiO thin films have a great potential for their integration and application in industry because it can be easily synthesized as thin coatings by magnetron sputtering. − In the case of electrochromic devices, a special attention is paid to the oxidation state of nickel according to the gas mixture. − NiO x films show a reversible modulation of its optical properties with respect to the applied voltage.…”