Experimental and theoretical analysis of influence of barrier composition on optical properties of GaN/AlGaN multi-quantum wells: Temperature- and pressure-dependent photoluminescence studies

Koronski, Kamil; Strąk, Paweł; Wierzbicka, Aleksandra; Grzanka, Ewa; Borysiuk, J.; Sobczak, Kamil; Jakieła, R.; Sobanska, M.; Kłosek, K.; Monroy, E.; Żytkiewicz, Z. R.; Krukowski, S.; Kamińska, A.

doi:10.1016/j.jallcom.2018.08.050

Cited by 11 publications

(8 citation statements)

References 46 publications

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“…The pressure coefficient of the polar structure (Figure 11b) is close to the value of 30 meV/GPa that was obtained from the DFT calculations for the 3 nm-wide n-doped MQWs with the same charge density of 2 × 10 19 cm −3 , but narrower 4 nm Al 0.25 Ga 0.75 N QBs [41]. These results are also in good accordance with the pressure behavior of 3 nm GaN single QWs with AlGaN QBs containing 30% of Al, which is reported by Teisseyre et al in [38].…”

Section: Pressure (Gpa)supporting

confidence: 83%

“…Non-polar systems are free from such negative features. Moreover, for polar QWs, the observed pressure coefficients of the PL energy (dE PL /dp) are reduced relative to those of the GaN energy gap [29][30][31][32][33][34][35][36][37][38][39][40][41]. This effect is caused by the hydrostatic-pressure-induced increase in the piezoelectric field in quantum structures [33][34][35]42].…”

Section: Introductionmentioning

confidence: 99%

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The Role of the Built-In Electric Field in Recombination Processes of GaN/AlGaN Quantum Wells: Temperature- and Pressure-Dependent Study of Polar and Non-Polar Structures

et al. 2022

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In this paper, we present a comparative analysis of the optical properties of non-polar and polar GaN/AlGaN multi-quantum well (MQW) structures by time-resolved photoluminescence (TRPL) and pressure-dependent studies. The lack of internal electric fields across the non-polar structures results in an improved electron and hole wavefunction overlap with respect to the polar structures. Therefore, the radiative recombination presents shorter decay times, independent of the well width. On the contrary, the presence of electric fields in the polar structures reduces the emission energy and the wavefunction overlap, which leads to a strong decrease in the recombination rate when increasing the well width. Taking into account the different energy dependences of radiative recombination in non-polar and polar structures of the same geometry, and assuming that non-radiative processes are energy independent, we attempted to explain the ‘S-shape’ behavior of the PL energy observed in polar GaN/AlGaN QWs, and its absence in non-polar structures. This approach has been applied previously to InGaN/GaN structures, showing that the interplay of radiative and non-radiative recombination processes can justify the ‘S-shape’ in polar InGaN/GaN MQWs. Our results show that the differences in the energy dependences of radiative and non-radiative recombination processes cannot explain the ‘S-shape’ behavior by itself, and localization effects due to the QW width fluctuation are also important. Additionally, the influence of the electric field on the pressure behavior of the investigated structures was studied, revealing different pressure dependences of the PL energy in non-polar and polar MQWs. Non-polar MQWs generally follow the pressure dependence of the GaN bandgap. In contrast, the pressure coefficients of the PL energy in polar QWs are highly reduced with respect to those of the bulk GaN, which is due to the hydrostatic-pressure-induced increase in the piezoelectric field in quantum structures and the nonlinear behavior of the piezoelectric constant.

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Section: Pressure (Gpa)supporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

The Role of the Built-In Electric Field in Recombination Processes of GaN/AlGaN Quantum Wells: Temperature- and Pressure-Dependent Study of Polar and Non-Polar Structures

et al. 2022

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“…In SL systems, both sublattices usually possess the same crystallographic structures, , and SLs with sublayers with two different crystallographic structures are very rarely presented . In this paper, we explore short-period {CdO/ZnO} n SLs with different thicknesses of ZnO and CdO layers, which were grown by plasma-assisted molecular beam epitaxy (PA-MBE) on m -oriented sapphire substrates.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Morphology of Short-Period {CdO/ZnO} Superlattices Grown by MBE

Przeździecka

Wierzbicka

Lysak

et al. 2021

Crystal Growth & Design

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The nanoscale morphology of short-period {CdO/ZnO} n superlattices (SLs) grown by plasma-assisted molecular beam epitaxy on m-oriented sapphire substrates is studied. The SL structures consist of 25 repetitions of subsequently deposited ZnO and CdO layers. X-ray diffraction (XRD) and transmission electron microcopy (TEM) studies confirm the presence of 2D SL structures with the wurtzite phase of ZnO sublayers and the rocksalt structure of CdO sublayers. For thicker ZnO sublayers, the (11̅.3) twinning was observed. The SL periods are calculated based on high-resolution XRD and TEM analyses. By varying the thickness of the CdO and ZnO sublayers, it is possible to control the energy gap in these quasi-alloys. These results suggest the promising potential of their optical properties for light emission and/or applications in the detection of visible to ultra-violet light.

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“…To obtain a modern InGaN/GaN LED with a high IQE, various device structures, such as a designed active region including double-heterostructures and multiple quantum wells (MQWs), the insertion of an electron-blocking layer, and an expanded current-spreading layer, have been investigated [2]. To date, IQEs of higher than 80% have been achieved for InGaN/GaN LEDs because of the rapid development of growth methods and technologies [8,9,10]. The LEE of InGaN/GaN LEDs is also a crucial factor in determining the EQE.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Light Extraction Efficiency for InGaN/GaN Light-Emitting Diodes Using Silver Nanoparticle Embedded ZnO Thin Films

et al. 2019

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In this study, we propose a liquid-phase-deposited silver nanoparticle embedded ZnO (LPD-Ag NP/ZnO) thin film at room temperature to improve the light extraction efficiency (LEE) for InGaN/GaN light-emitting diodes (LEDs). The treatment solution for the deposition of the LPD-Ag/NP ZnO thin film comprised a ZnO-powder-saturated HCl and a silver nitrate (AgNO3) aqueous solution. The enhanced LEE of an InGaN/GaN LED with the LPD-Ag NP/ZnO window layer can be attributed to the surface texture and localized surface plasmon (LSP) coupling effect. The surface texture of the LPD-Ag/NP ZnO window layer relies on the AgNO3 concentration, which decides the root-mean-square (RMS) roughness of the thin film. The LSP resonance or extinction wavelength also depends on the concentration of AgNO3, which determines the Ag NP size and content of Ag atoms in the LPD-Ag NP/ZnO thin film. The AgNO3 concentration for the optimal LEE of an InGaN/GaN LED with an LPD-Ag NP/ZnO window layer occurs at 0.05 M, which demonstrates an increased light output intensity that is approximately 1.52 times that of a conventional InGaN/GaN LED under a 20-mA driving current.

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Experimental and theoretical analysis of influence of barrier composition on optical properties of GaN/AlGaN multi-quantum wells: Temperature- and pressure-dependent photoluminescence studies

Cited by 11 publications

References 46 publications

The Role of the Built-In Electric Field in Recombination Processes of GaN/AlGaN Quantum Wells: Temperature- and Pressure-Dependent Study of Polar and Non-Polar Structures

The Role of the Built-In Electric Field in Recombination Processes of GaN/AlGaN Quantum Wells: Temperature- and Pressure-Dependent Study of Polar and Non-Polar Structures

Nanoscale Morphology of Short-Period {CdO/ZnO} Superlattices Grown by MBE

Enhancement of Light Extraction Efficiency for InGaN/GaN Light-Emitting Diodes Using Silver Nanoparticle Embedded ZnO Thin Films

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