Nanoscale investigation of enhanced electron field emission for silver ion implanted/post-annealed ultrananocrystalline diamond films

Abstract

Silver (Ag) ions are implanted in ultrananocrystalline diamond (UNCD) films to enhance the electron field emission (EFE) properties, resulting in low turn-on field of 8.5 V/μm with high EFE current density of 6.2 mA/cm2 (at an applied field of 20.5 V/μm). Detailed nanoscale investigation by atomic force microscopy based peak force-controlled tunneling atomic force microscopy (PF-TUNA) and ultra-high vacuum scanning tunneling microscopy (STM) based current imaging tunneling spectroscopy (CITS) reveal that the UNCD grain boundaries are the preferred electron emission sites. The two scanning probe microscopic results supplement each other well. However, the PF-TUNA measurement is found to be better for explaining the local electron emission behavior than the STM-based CITS technique. The formation of Ag nanoparticles induced abundant sp2 nanographitic phases along the grain boundaries facilitate the easy transport of electrons and is believed to be a prime factor in enhancing the conductivity/EFE properties of UNCD films. The nanoscale understanding on the origin of electron emission sites in Ag-ion implanted/annealed UNCD films using the scanning probe microscopic techniques will certainly help in developing high-brightness electron sources for flat-panel displays applications.

Origin of Conductive Nanocrystalline Diamond Nanoneedles for Optoelectronic Applications

“…The variation in the FEE characteristics is plotted in Figure b and also tabulated in Table . It can be clearly noted that lower the resistivity of the films better the FEE properties comparable to those of the conducting diamond films reported. ,− …”

Single Nanoparticle Activities in Ensemble: A Study on Pd Cluster Nanoportals for Electrochemical Oxygen Evolution Reaction

“…55,56 PF-TUNA works on the same principle as conductive AFM (CAFM); however, in CAFM (or traditional TUNA operated in contact mode) fine control of lateral shear forces is difficult, which makes their use challenging or even impossible for fragile samples and soft materials. 57,58 Instead, PF-TUNA can measure current each time the tip gets in contact with the surface during the continuous acquisition of force curves in peak force tapping mode, and, as a result of the extremely sensitive force control and dramatic reduction in shear forces, very fragile and challenging samples can be measured. Also, in contrast to standard STM-based current imaging tunneling spectroscopy, where measurements require sample surfaces to be smooth at the nanometer scale, PF-TUNA can investigate surfaces featuring RMS roughness of several micrometers with very high current sensitivity (current measurement range from sub-pA to 120 nA, and noise level of 50 fA).…”

“…Active SNPEs were detected by PF-TUNA, a technique based on the electric contact formed between the conductive AFM tip and the sample surface. Its working principle is schematically explained in Figure S2a: by applying a bias voltage between the tip and the sample, the resulting current through the sample can be measured with a current amplifier. , PF-TUNA works on the same principle as conductive AFM (CAFM); however, in CAFM (or traditional TUNA operated in contact mode) fine control of lateral shear forces is difficult, which makes their use challenging or even impossible for fragile samples and soft materials. , Instead, PF-TUNA can measure current each time the tip gets in contact with the surface during the continuous acquisition of force curves in peak force tapping mode, and, as a result of the extremely sensitive force control and dramatic reduction in shear forces, very fragile and challenging samples can be measured. Also, in contrast to standard STM-based current imaging tunneling spectroscopy, where measurements require sample surfaces to be smooth at the nanometer scale, PF-TUNA can investigate surfaces featuring RMS roughness of several micrometers with very high current sensitivity (current measurement range from sub-pA to 120 nA, and noise level of 50 fA). ,− This enabled the electrical characterization of nanoportals in the catalyst samples with high lateral resolution, in contrast to traditional measurements that would require the sample surface to be sufficiently conductive and smooth.…”

Diffraction diamond grating formed by silver-ion mask implantation

“…The silver nanoparticles synthesized in the DOE structure could allow using their plasmon properties to control the choice of optical constants in the DOE structure, similarly to how it was previously realized on silicate glasses and polymers [11][12][13]. It should be noted that attempts to implant diamond with ions of noble metals (gold and silver) were made earlier https://doi.org/10.1016/j.vacuum.2019.03.045 Received 6 March 2019; Accepted 22 March 2019 T [16][17][18], but the creation of DOEs in the mentioned experiments was not implemented.…”