Effect of the 0.94, 1.0, 1.2, and 1.3 ev radiative centres on the intrinsic luminescence intensity in n-GaAs

Abstract

The relative role of radiative and non‐radiative recombination centres in the decrease of the intrinsic luminescence intensity Icv in n‐type GaAs crystals at different doping levels (n0 = 5 × × 1016 to 6 × 1018 cm−3), excitations (L = 1018 to 3 × 1020 quanta/cm2 s), and temperatures (T = 77 to 600 K) is studied. It is shown that both the radiative r‐centres (the electron recombination via these centres gives rise to the emission bands at hvm(77 K) = 0.94, 1.0, 1.2, and 1.3eV) as well as non‐radiative s‐centres could play an essential role in the decrease of Icv. The low quantum efficiency of intrinsic emission η of moderately doped n‐type GaAs crystals (2 × 1017 cm−3 ≦ ≦ n0 ≦ 3 ≦ 1018 cm−3) at low temperatures and low excitation intensities is caused by r‐centres. The low quantum efficiency of intrinsic emission of lightly (n0 < 2 × 1017 cm−3) and heavily (n0 < 3 × 1018 cm−3) doped n‐type GaAs crystals at all temperatures and excitation intensities and moderately doped n‐type GaAs crystals at high temperatures or at high excitation intensities is caused by s‐centres.

Temperature dependence of defect-related photoluminescence in III-V and II-VI semiconductors

“…20 Williams 66 explained the temperature dependence of the 1.2 eV PL intensity by the Seitz-Mott mechanism and attributed the activation energy of 0.18 eV to a barrier between the excited and ground state of the luminescence center. Later, however, Glinchuk and Prokhorovich 9,27 observed the characteristic competition between the recombination channels and unambiguously proved that the PL quenching occurs via the Sch€ on-Klasens mechanism for the V Ga D acceptors.…”

“…If the activation energy in the thermal quenching process is close to this value, it is reasonable to attribute the quenching to the Sch€ on-Klasens mechanism (the emission of holes to the valence band in n-type or electrons to the conduction band in p-type). Examples of such identification of the quenching mechanism include a number of defects in CdTe, 30,31 ZnSe, 64 GaAs, 27 GaP, 28 and GaN. 6 In the latter case, the activation energy of the quenching nearly coincides with the ionization energies of acceptors responsible for the YL (peak at 2.2 eV), BL (2.9 eV), and BL2 (3.0 eV) bands.…”

“…Four of these bands were identified as different complexes involving vacancies and impurities. 27 The quenching of these PL bands is attributed to the thermal emission of holes from the acceptors to the valence band. This mechanism is supported by a coherent rise of the near-band-edge PL intensity, in agreement with the rate-equation model discussed in Sec.…”

Tunable and abrupt thermal quenching of photoluminescence in high-resistivity Zn-doped GaN

“…Thermal quenching of the electron recombination currents sometimes produces clear steps in temperature dependences of PL intensity. 13,47,48 The latter process can be modeled with rate equations that permit the current steps to be extrapolated back to low temperature, and that is what we do in our calibration procedure described below.…”

Electroluminescence « à 1 eV » des diodes laser D.H. GaAs/(Ga, Al)As

“…Dans le domaine spectral 0,90 à 1,20 eV, trois raies sont très citées dans la littérature pour GaAs type n à 77 K : les positions sont 0,94 eV, 1,0 eV, 1,20 eV. K. D. Glinchuk et al [10] ont attribué la raie à 0,94 eV au complexe VGa-VAs.…”