Characterization of deep-level defects in GaNAs/GaAs heterostructures grown by APMOVPE

Activation energy Ea, apparent capture cross section σa and concentration NT obtained from the conventional DLTS and Laplace DLTS analysis of the trap E4 observed in the GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %) in high-temperature spectra (>300 K)_ In the last column, possible identity of the trap has been proposed_

GaNAs/GaAs samples	E4 (EL2)					Possible identity
	DLTS			LDLTS
	NT [cm−3]	Ea [eV]	σa [cm2]	Ea [eV]	σa [cm2]
1.2% N	2.3 × 1013	0.81	2.4 × 10−14	0.81	7.7 × 10−14	EL2a–c
1.6 % N	2.0 × 1013	0.80	1.2 × 10−14	0.80	3.8 × 10−14
2.7 % N	2.6 × 1013	0.81	1.9 × 10−14	0.80	2.3 × 10−14

Concentration of the electron traps E1, E2 and E3 obtained from DLTS measurements of the GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %)_

GaNAs/GaAs	E1 (N-related)	E2 (EL6)	E3 (EL3)
	NT [cm−3]	NT [cm−3]	NT [cm−3]
1.2 % N	1.3 × 1013	2.1 × 1013	1.1 × 1013
1.6 % N	1.8 × 1013	4.5 × 1013	4.2 × 1013
2.7 % N	1.6 × 1013	7.0 × 1013	4.5 × 1013

Activation energies (Ea) and apparent capture cross sections (σa) obtained from conventional DLTS and Laplace DLTS analysis of the traps E1, E2 and E3 observed in GaNxAs1−x/GaAs samples (x = 1_2 % to 2_7 %) in low-temperature spectra (<300 K)_ In the last column, possible identities of the traps have been made on the basis of comparison with activation energies of the defects observed in as-grown GaAs and GaNAs, as reported in the references given below_

Trap label	1.2 % N		GaNAs/GaAs 1.6 % N				2.7 % N		Possible identity
	DLTS		DLTS		LDLTS		DLTS
	Ea [eV]	σa [cm2]	Ea [eV]	σa [cm2]	Ea [eV]	σa [m2]	Ea [eV]	σa [cm2]
E1	0.24	8.8 × 10−18	0.21	2.9 × 10−18	0.20	3.4 × 10−18	0.15	2.1 × 10−18	N-relateda−d
E2	0.32	1.7 × 10−16	0.32	2.5 × 10−16	0.30	6.6 × 10−16	0.32	1.6 × 10−16	EL6e−g
E3	0.49	3.9 × 10−13	0.49	3.2 × 10−14	0.48	1.5 × 10−14	0.49	5.2 × 10−14	EL3f−h