Mechanisms of Field Emission from Cubic Boron Nitride Coated Molybdenum Emitters

1998 ◽  
Vol 509 ◽  
Author(s):  
R. Schlesser ◽  
B.L. Mccarson ◽  
Z. Sitar
Keyword(s):  
Boron Nitride ◽  
Field Emission ◽  
Voltage Drop ◽  
Cubic Boron Nitride ◽  
Emission Current ◽  
Flat Band ◽  
Ohmic Resistance ◽  
Before And After ◽  
Voltage Dependent ◽  
Feed Analysis

AbstractA combination of classical I-V characterization and voltage-dependent field emission energy distribution (V-FEED) analysis was employed to investigate the mechanisms that dominate field emission from tip-shaped Mo emitters electrophoretically coated with nominally intrinsic, cubic boron nitride (c-BN) powders. I-V characterization of Mo emitters before and after coating showed that the c-BN coating enhanced the field emission current by 2 orders of magnitude. V-FEED analysis revealed a voltage drop proportional to the applied voltage across the c-BN coating due to field penetration. This voltage drop was typically in the order of several Volts for applied voltages of several 100 Volts, and a cathode-to-anode distance of 500 μm. Extrapolation of V-FEED data to flat band condition identified the conduction band minimum of c-BN as the origin of field emitted electrons. At larger field emission currents, an additional voltage drop was observed and was found to be proportional to the emission current. This observation was interpreted in terms of an ohmic resistance at the Mo/c-BN interface and was estimated to be in the order of 10 MΩ.

Voltage Dependent Field Emission Energy Distribution Analysis of Wide Bandgap Materials

1998 ◽  
Vol 509 ◽  
Author(s):  
B.L. Mccarson ◽  
R. Schlesser ◽  
Z. Sitar
Keyword(s):  
Energy Distribution ◽  
Field Emission ◽  
Electron Emission ◽  
Wide Bandgap ◽  
Emission Energy ◽  
Wide Bandgap Material ◽  
Voltage Dependent ◽  
Feed Analysis ◽  
Wide Bandgap Materials ◽  
Dependent Field

AbstractField emission from wide bandgap materials was investigated through voltage dependent field emission energy distribution (V-FEED) analysis. As compared to classical I-V characterization, V-FEED analysis can provide additional, detailed information about the origin of and the mechanism responsible for the field emission of electrons. The V-FEED technique consists of measuring the energy distribution of field emitted electrons collected at various extraction voltages. By measuring changes in the energy of the field emission peak at different voltages, data can be extrapolated to flat-band condition to determine the energy of the band from which the electron emission originated. In this study, field emission from cubic boron nitride (c-BN) coated and diamond coated tip-shaped Mo emitters was examined. For the nominally intrinsic wide bandgap coating materials studied, a linear voltage drop across the wide bandgap material, usually on the order of 1% of extraction voltage was observed and explained by field induced band-bending. For the intrinsic c-BN and diamond samples studied, the electron emission originated from the conduction band minimum at the wide bandgap material/vacuum interface.

Electron field emission from nanostructured cubic boron nitride islands

2008 ◽  
Vol 92 (1) ◽  
pp. 013115 ◽  
Author(s):  
Kungen Teii ◽  
Seiichiro Matsumoto ◽  
John Robertson
Keyword(s):  
Boron Nitride ◽  
Field Emission ◽  
Cubic Boron Nitride ◽  
Electron Field Emission ◽  
Electron Field

Field Emission Characteristics of Orthorhombic Boron Nitride Films

2008 ◽  
Vol 368-372 ◽  
pp. 650-652
Author(s):  
Wei Qing Li ◽  
Yong Nian Zhao
Keyword(s):  
Thin Films ◽  
Boron Nitride ◽  
Electric Field ◽  
Field Emission ◽  
Current Density ◽  
Emission Current Density ◽  
Emission Current ◽  
Vacuum System ◽  
Emission Characteristics ◽  
System A

Orthorhombic boron nitride (o-BN) films with various thickness (150, 220 and 300nm etc.) are prepared on Si(100) substrate by radio frequency plasma enhanced pulsed (Nd:YAG) laser deposition (RF-PEPLD) in Ar-N2 gas system. The films are characterized by Fourier transform infrared spectroscopy and atomic force microscopic. The field emission characteristics of the BN thin films are measured in an ultrahigh vacuum system. A threshold electric field of 8V /6m and the highest emission current density of 157.5mA/cm2 at an electric field of 20V/6m are obtained for the 150nm-thick BN film and a threshold electric field of 18V / 6m and the highest emission current density of 332.9mA/cm2 at an electric field of 52 V/6m are obtained for the 220nm-thick BN film. The results show that the threshold electric field increases with increasing thickness of the films, while the withstand voltage characteristic of the BN films also increases with increasing thickness of the films. The Fowler-Nordheim plots show that electrons emitted from BN to vacuum by tunneling through the potential barrier at the surface of BN thin films.

Field emission mechanism from nanocrystalline cubic boron nitride films

2004 ◽  
Vol 35 (4) ◽  
pp. 371-374 ◽  
Author(s):  
B. Wang ◽  
R.Z. Wang ◽  
H. Zhou ◽  
X.H. Yan ◽  
J.X. Cao ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Field Emission ◽  
Cubic Boron Nitride ◽  
Emission Mechanism ◽  
Boron Nitride Films

Structural relationships in the synthesis of cubic boron nitride thin films by ion-assisted deposition

1994 ◽  
Vol 52 ◽  
pp. 638-639
Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty
Keyword(s):  
Boron Nitride ◽  
Ion Irradiation ◽  
Cubic Boron Nitride ◽  
Film Stress ◽  
Bonded Phases ◽  
Structural Relationships ◽  
Precursor Material ◽  
Pressure Synthesis ◽  
Microstructure Of The Material

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.

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