Acceptor formation in Mg-doped, indium-rich GaxIn1-xN: evidence for p-type conductivity.
We report on the Mg-doped, indium-rich GaxIn1-xN (x < 30). In the undoped material, the intrinsic electron density is very high and as a result there is no detectable photoconductivity (PC) signal within the range of temperatures of 30 <T < 300 K. In the Mg-doped material however, where the conductivity is reduced, there is a strong PC spectrum with two prominent low-energy peaks at 0.65 and 1.0 eV and one broad high-energy peak at around  1.35 eV. The temperature dependence of the spectral photoconductivity under constant illumination intensity,  at T > 150 K, is determined by the longitudinal-optical phonon scattering together with the thermal regeneration of non-equilibrium minority carriers from traps with an average depth of 103 ± 15 meV. This value is close to the Mg binding energy in GaInN. The complementary measurements of transient photoluminescence at liquid He temperatures give the e-A0 binding energy of approximately 100 meV. Furthermore, Hall measurements in the Mg-doped material also indicate an activated behaviour with an acceptor binding energy of 108 ± 20 meV.
Department of Computer Science and Electronic Engineering, University of Essex, Colchester, CO4 3SQ, UK. balkan@essex.ac.uk.
Naci
N
Balkan
Engin
E
Tiras
Ayse
A
Erol
Mustafa
M
Gunes
Sukru
S
Ardali
McEtin
M
Arikan
Dalphine
D
Lagarde
Helene
H
Carrère
Xavier
X
Marie
Cebrail
C
Gumus