Facile synthesis and electron transport properties of NiO nanostructures investigated by scanning tunneling microscopy

Abstract

Due to their unique chemical, thermal, electronic and photonic properties, low -dimensional transition metal oxides, especially NiO, have attracted great deal of attention for potential applications in a wide range of technologies, such as, sensors, electrochromic coatings and self-healing materials. However, their synthesis involves multi-step complex procedures that in addition to being expensive, further introduce impurities. Here we present a low cost facile approach to synthesize uniform size NiO nanoparticles (NPs) from hydrothermally grown Ni(OH)2. Detailed transmission electron microscopic analysis reveal the average size of NiO NPs to be around 29 nm. The dimension of NiO NP is also corroborated by the small area scanning tunneling microscope (STM) measurements. Further, we investigate electron transport characteristics of newly synthesized Ni(OH)2 and NiO nanoparticles on p-type Si substrate using scanning tunneling microscopy. The conductivity of Ni(OH)2 and NiO are determined to be 1.46x10-3 S/cm and 2.37x10-5 S/cm, respectively. The NiO NPs exhibit a lower voltage window (∼0.7 V) electron tunneling than the parent Ni(OH)2.

Green-based bio-synthesis of nickel oxide nanoparticles in Arabic gum and examination of their cytotoxicity, photocatalytic and antibacterial effects

“…The second and third stages of weight losses reported to be 10% and 16%, occurred in the temperature range of 161-316°C and 316-347°C, respectively. These losses were attributed to the degradation of organic compounds and the removal of nitrates, as well as the decomposition of nickel complexes (53). In conformity to the DTA chart, the exothermic peaks are associated with these particular developments.…”

Microfluidic Processing of Ligand‐Engineered NiO Nanoparticles for Low‐Temperature Hole‐Transporting Layers in Perovskite Solar Cells

“…[ 52 ] This approach is found to promote high‐pressure mixing of low‐volume liquids, thereby yielding homogeneous dispersions of NiO NPs just prior to the deposition process to enable highly conformal films. Consistent with lower tunneling barriers, [ 53 ] field‐effect transistor (FET) measurements of the surface‐modified NiO showed appreciable enhancements to the hole mobility for short‐chained ligands compared with neat OA. Moreover, the cubic NiO NP films were assessed as HTLs within p−i−n PSCs.…”

“…To the best of our knowledge, the devices fabricated using NiO BF 4 mark the highest PSC efficiency achieved to date using low temperature (<150 C). [53,79,[83][84][85] The incident photon-to-current efficiency (IPCE) measurements of these devices are shown in Figure 4d. Integrated photocurrent approximations are in good agreement with those obtained from JÀV measurements.…”

NiO-Based Electronic Flexible Devices

“…Transition metal oxides and particularly NiO have the advantage of high storage capacitance [52], optical and electrical properties [53], transport properties on surfaces [54] as well as in perovskite solar cells [55]. Their nanoparticles synthesis may be achieved in several, environmentally friendly ways [56][57][58][59][60][61][62][63], with several shapes, arrangements, and super-structures [64].…”