Anneal-induced interdiffusion in 1.3-μmGaInNAs∕GaAs quantum well structures grown by molecular-beam epitaxy

Abstract

Articles you may be interested inGaInNAs double-barrier quantum well infrared photodetector with the photodetection at 1.24 μ m Appl. Phys. Lett. 91, 051102 (2007); 10.1063/1.2767185GaInNAs/GaAs quantum wells grown by molecular-beam epitaxy emitting above 1.5 μm Appl.High-resolution x-ray diffraction ͑HRXRD͒ and photoluminescence ͑PL͒ have been used to study the diffusion of atoms in 8-nm Ga 0.628 In 0.372 N 0.015 As 0.985 / GaAs quantum well, with and without dielectric encapsulants. These samples were repeatedly annealed in the temperature range of 680-800°C over times of up to 16 000 s. HRXRD simulations, by using dynamic scattering theory and Fick's diffusion model with a constant diffusion coefficient, demonstrate that the diffusion lengths are shorter than 2 nm under the annealing conditions studied. In this range of diffusion lengths, the transition energy E e1−Hh1 , numerically calculated from the Schrödinger equation using a potential derived from the diffusion equation, increases linearly as the square of the diffusion length. The steady-state PL blueshifts, after a fast initial blueshift due to the rearrangement of local nitrogen bonding configurations N-Ga m In 4−m ͑0 ഛ m ഛ 4͒, otherwise known as short-range order, as a function of annealing time are well fitted by using the linear function. The values of ⌬E SRO and diffusion coefficients obtained are 18-28 meV and 3.0ϫ 10 −20 -3.5ϫ 10 −18 cm 2 / s, respectively. The activation energy characterized from the diffusion coefficients at different temperatures is 3.25 eV and is not affected by the dielectric encapsulates.

Anneal-induced structural changes of GaIn(N)As/Ga(N)As multiple quantum wells grown by molecular beam epitaxy

“…[11] on assumption that the QWs retain their square shape and alloy homogeneity, while dissolving the barriers during annealing. No nitrogen diffusion was considered in the simulations [12,13]. It should be noted that the incorporation of N is found to modify the In concentration profile for the as-grown samples due to In-surface segregation [14].…”

Effects of annealing on structural and optical properties of InGaN/GaN multiple quantum wells at emission wavelength of 490 nm

“…13 Theoretical calculations of the ground transition energy for InGaN/GaN MQWs with various QW thicknesses and In compositions are shown in Fig. 3.…”

Photoluminescence probing of interface evolution with annealing in InGa(N)As/GaAs single quantum wells

“…Liu et al studied annealing effect on 8nm-thick In 0.372 Ga 0.628 N 0.015 As 0.985 /GaAs SQW and concluded that annealing-induced interdiffusion length of 2 nm corresponds to PL peak blueshift of 18-28 meV. 25 Bouragba et al indicated that while a nitrogen free InGaAs/GaAs SQW sample shows the In-Ga interdiffusion, the introduction of nitrogen moderately enhances the phenomenon. 30 Shirakata et al indicated that for 10-nm-thick In 0.32 Ga 0.68 N 0.01 As 0.99 / GaAs SQW, annealing improves the crystal quality to be comparable with that of corresponding N-free sample.…”

“…20,21 The evolution of PL peak energy manifested pronounced S-shape for the dilute-N InGaNAs/GaAs single quantum wells (SQWs) at low temperatures, and followed the empirical Varshni model in the high-temperature region with significant reduction in the temperature dependence as compared to the N-free sample. [22][23][24][25] However, (i) controversies remained that while the drastic blueshift after annealing was considered as a result of the N content and/or the N-related localized level in the QW layer but not the In-Ga interdiffusion, 20,23,24 it was indicated that the annealing alone may induce interdiffusion in a length of 2 nm; 25 and (ii) while an exciton binding energy was derived to be about 6.5 meV for In 0.05 Ga 0.95 As/GaAs QW with a 8-nm-thick well layer, 26 a very small N content of about 0.5% in a 6-nm In 0.4 Ga 0.6 N 0.005 As 0.995 /GaAs SQW was shown to increase surprisingly the exciton binding energy by nearly 80% relative to the referential InGaAs/GaAs SQW to a value of about 17.5 meV. 27 In this work, the RTA effects on InGa(N)As/GaAs SQWs are characterized by PL measurements at different a)…”