Conductivity and Hall effect of free-standing highly resistive epitaxial GaN:Fe substrates

Abstract

Free-standing highly resistive Fe-doped GaN layers grown by hydride vapor phase epitaxy were characterized by temperature-dependent conductivity and Hall effect measurements. Samples with a room-temperature resistivity of 1.6×107–6×108Ωcm and a Hall mobility of ∼330cm2V−1s−1 showed simple band conduction with the mobility power x=−1.5 and an activation energy 0.58–0.60eV, which can be attributed to a Fe acceptor. Samples with a lower mobility, ⩽10cm2V−1s−1, exhibited an increase of the mobility with temperature. Here, the conduction seems to be strongly influenced by potential barriers at inhomogeneities, with an activation energy of 0.21eV and a barrier height of 0.14–0.18eV. The activation energy 0.36 and 0.40eV, evaluated from the resistivity measurements, does not correspond to that of the Fe acceptor.

AB INITIO INVESTIGATIONS OF THE MAGNETISM IN DILUTED MAGNETIC SEMICONDUCTOR Fe-DOPED GaN

“…4(b)], Fe-doped GaN is a semiconductor with a much smaller bandgap (∼ 0.6 eV) than pure GaN, in agreement with the experimental data of a small activation energy (0.58-0.60 eV) in Fe-doped GaN attributed to a Fe acceptor. 33 Spin calculations are also consistent with fix-spin-magnetic calculations of the ground state DOS. 6 The partial DOS of GaN and Fe-doped GaN in the lower panel of Fig.…”

Photoinduced current transient spectroscopy of deep levels and transport mechanisms in iron-doped GaN thin films grown by low pressure-metalorganic vapor phase epitaxy

“…[1][2][3][4] As in other III-V semiconductors, transition metals containing a number of d electrons close to five ͑Cr, Mn, Fe͒ behave as deep acceptors, like Fe in InP, 5 and can be useful for compensating unintentional donors. [1][2][3][4] As in other III-V semiconductors, transition metals containing a number of d electrons close to five ͑Cr, Mn, Fe͒ behave as deep acceptors, like Fe in InP, 5 and can be useful for compensating unintentional donors.…”

Photoelectric properties of highly excited GaN:Fe epilayers, grown by modulation- and continuous-doping techniques

“…cathodoluminescence provided a binding energy of Fe-hole complex E a E0.24 eV for GaN:Fe [4]). Temperature-dependent conductivity and Hall studies [13] showed in counterpart that good-quality freestanding GaN:Fe is very weakly ntype, and in such a case E a E0.6 eV. On the other hand, the same group could not measure carrier origin in our MD specimens, and deduced E a from resistivity to be 0.2-0.3 eV [14].…”