Growth, physical and electrical characterization of nickel oxide thin films prepared by plasma-enhanced atomic layer deposition using nickelocene and oxygen precursors

Abstract

Nickel oxide (NiO) thin films are prepared by plasma-enhanced atomic layer deposition using nickelocene (NiCp 2 ) and oxygen (O 2 ) precursors. The effects of process parameters on the growth rate of NiO film are investigated, including deposition temperature, NiCp 2 pulse time, and O 2 plasma pulse time. In terms of deposition temperatures between 225 and 275°C, a stable growth rate of ∼0.17 Å/cycle is obtained, meanwhile, the deposited films contain Ni(II)−O, Ni(III)−O, Ni(II)−OH, C−C bonds and metallic Ni atoms, and exhibit a smooth surface with root-mean-square roughness of 0.37 nm. As the deposition temperature increases from 150 to 350°C, the deposited NiO film changes from an amorphous state to a NiO (200) orientation-dominated texture and further to NiO (111) and (200) orientations concomitant polycrystalline one; at the same time, the transmittance of the film shows a decline tendency, and the optical band gap decreases from 3.69 to 3.48 eV. Furthermore, it is found that the deposited NiO film behaves like a dielectric rather than a semiconductor, and for the NiO film deposited at 250°C, a dielectric constant of 16.7 is demonstrated together with a film composition of 51.6% Ni, 40% O and 8.4% C.

Oxides for Rectenna Technology

“…Hence, the measured band gap and permittivity can vary even for similarly prepared oxide films. Table 4 depicts measured values of static and dynamic permittivity for most commonly used oxides in MIM diodes for rectenna, such as NiO [105][106][107][108][109], Al 2 O 3 [110][111][112][113][114][115][116][117][118][119], ZnO [108,[120][121][122], TiO 2 [114,119,[123][124][125][126][127][128], CuO [8,129,130], Ta 2 O 5 [91,108,113,126,131], Nb 2 O 5 [17,51,91,108], Cr 2 O 3 [132,133], SiO 2 [114,119], HfO 2 [114,134,135], V 2 O 5…”

Plasma-enhanced atomic layer deposition of nickel and cobalt phosphate for lithium ion batteries

“…For the deposition of nickel phosphate in this work, the metal-organic precursor of choice became nickelocene, inspired by our earlier work on PE-ALD of cobalt phosphate and as this precursor has already proven to be successful towards PE-ALD of nickel oxide. 27 In addition to studying the deposition of this nickel phosphate, its electrochemical activity will be investigated together with that of PE-ALD deposited cobalt phosphate (resulting from the already reported PE-ALD process 26 ) and compared to the already reported PE-ALD deposited iron phosphate for reference. In this work, only the electrochemical activity of both layers will be studied (i.e.…”

One-step chemical vapor deposition fabrication of Ni@NiO@graphite nanoparticles for the oxygen evolution reaction of water splitting

“…Therefore, at lower temperatures, the hydrocarbon hardly reacts with oxygen, resulting in most of the oxygen being able to fully oxidize Ni to form NiO nanoparticles, as well as a great deal of amorphous carbon on the surface. On the other hand, at a higher temperature, the large amount of hydrocarbon easily reacts with oxygen 35 and consumes it, leading to only a small part of oxygen partially oxidizing Ni to form Ni@NiO core–shell nanoparticles, while carbon crystallizes to graphite due to the high temperature or catalysis of Ni. Furthermore, the CO concentration increases with increasing temperature, 34 resulting in a reducing atmosphere to form Ni easily at 800 °C, as shown in Fig.…”