Figures index


Electric Properties of n-GaN: Effect of Different Contacts on the Electronic Conduction

S. Abdalla, F. Marzouki, S. Al-ameer, S. Turkestani

International Journal of Physics. 2013, 1(2), 41-48 doi:10.12691/ijp-1-2-3
  • Figure 1. I –VT curves for n-type Al-GaN for different temperatures. The slope of these lines increases with temperature T and is directly proportional to the electrical conductivity σΩ1cm-1).
  • Figure 2. Electrical conductivity of n-GaN as a function of temperature: The solid line represents the calculated values after equation (1); it is calculated using Eq. (1) with 2 distinct activation energies at ΔE = 0.23 EV and 0.013EV while open squares designate the experimental values
  • Figure 3. Fermi level energy as a function of temperature: at high temperature EF varies linearly as EF = 0.17 – 2.63 x10-4TeV and at low temperature EF varies linearly as EF = 0.0897 + 5.34 x10-4eV
  • Figure 4. The electron density n0, calculated after Eq. (2) is presented as a function of temperature: the effect of both deep (EL1) and shallow (EL2) trapping levels are clearly shown at 0.22eV and 0.013eV respectively
  • Figure 5. The electron mobility, μ as a function of temperature; two clear scattering mechanisms are present: (1) at low temperatures where μα T0.95 (scattering on impurity centers) and (2) at high temperatures where μα T-1.14(scattering on lattice defects)
  • Figure 6. I – VT characteristics of Au-nGaN; solid lines represent calculated values after equation (7) at 80K and at 300K. Triangles symbolize the experimental values at 300K and squares denote the experimental values at 80K
  • Figure 7. the natural logarithm of the current density ln(J) as a function of the applied potential Vappl for different temperatures
  • Figure 8. Energy band-diagram corresponding to room temperature for Au-n-GaN metal-semiconductor contact
  • Figure 9. the Deep level transient spectroscopy signals as a function of temperature
  • Figure 10. The temperature dependence of the ideality factor, n: Open triangles stand for values obtained after the slope of ln J curves when we neglecting the series resistance Rs and open stars represent n as fitting parameter of I-V curves with Eq. (7) when neglecting the presence of Rs. where Rs0 and α are constants: Rs0 = 21.18 Ω and α = 3.85 x 10-3K-1. This decaying behavior indicates that Rs has some semiconducting properties.