Optical Properties of AlGaN Quantum Well Structures

We demonstrate 230-250 nm efficient ultraviolet (UV) photoluminescence (PL) from AlN(AlGaN)/AlGaN multi-quantum-wells (MQWs) fabricated by metal-organic vapor-phase-epitaxy (MOVPE). Firstly, we show the PL properties of high Al content AlGaN bulk (Al content: 85-95%) emitting from near band-edge. We systematically investigated the PL properties of AlGaN-MQWs consisting of wide bandgap AlGaN (Al content: 53-100%) barrier. We obtained efficient PL emission of 234 and 245 nm from AlN/Al0.18Ga0.82N and Al0.8Ga0.2N/Al0.18Ga0.82N MQWs, respectively, at 77 K. The optimum value of well thickness was approximately 1.5 nm. The emission from the AlGaN MQWs were several tens of times stronger than that of bulk AlGaN. We found that the most efficient PL is obtained at around 240 nm from AlGaN MQWs with Al0.8Ga0.2N barriers. Also, we found that the PL from AlGaN MQW is as efficient as that of InGaN QWs at 77 K.

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Optical Properties of AlGaN Quantum Well Structures

MRS Proceedings ◽

10.1557/proc-595-f99w11.35 ◽

1999 ◽

Vol 595 ◽

Cited By ~ 1

Author(s):

Hideki Hirayama ◽

Yasushi Enomoto ◽

Atsuhiro Kinoshita ◽

Akira Hirata ◽

Yoshinobu Aoyagi

Keyword(s):

Optical Properties ◽

Quantum Well ◽

Quantum Wells ◽

Vapor Phase ◽

Wide Bandgap ◽

Near Band Edge ◽

Quantum Well Structures ◽

Al Content ◽

Pl Emission ◽

High Al Content

AbstractWe demonstrate 230-250 nm efficient ultraviolet (UV) photoluminescence (PL) from AlN(AlGaN)/AlGaN multi-quantum-wells (MQWs) fabricated by metalorganic vapor-phase-epitaxy (MOVPE). Firstly, we show the PL properties of high Al content AlGaN bulk (Al content: 85-95%) emitting from near band-edge. We systematically investigated the PL properties of AlGaN-MQWs consisting of wide bandgap AlGaN (Al content: 53-100%) barrier. We obtained efficient PL emission of 234 and 245 nm from AlN/Al0.18Ga0.82N and Al0.8Ga0.2N/Al0.18Ga0.82N MQWs, respectively, at 77 K. The optimum value of well thickness was approximately 1.5 nm. The emission from the AlGaN MQWs were several tens of times stronger than that of bulk AlGaN. We found that the most efficient PL is obtained at around 240 nm from AlGaN MQWs with Al0.8Ga0.2N barriers. Also, we found that the PL from AlGaN MQW is as efficient as that of InGaN QWs at 77 K.

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In Segregation Effects on Optical and Doping Properties of InAlGaN Quaternary for UV Emitting Devices

MRS Proceedings ◽

10.1557/proc-639-g2.8 ◽

2000 ◽

Vol 639 ◽

Cited By ~ 3

Author(s):

Hideki Hirayama ◽

Atsuhiro Kinoshita ◽

Takuya Yamanaka ◽

Akira Hirata ◽

Yoshinobu Aoyagi

Keyword(s):

Room Temperature ◽

Hole Concentration ◽

Single Quantum Well ◽

Al Content ◽

Organic Vapor ◽

Band Emission ◽

Uv Emission ◽

Micron Size ◽

Metal Organic ◽

High Al Content

ABSTRACTWe demonstrate room temperature intense ultraviolet (UV) emission wavelength ranging 300- 340 nm from InxAlyGa1-x-yN quaternary alloys grown by metal-organic vapor-phase-epitaxy (MOVPE). We found that the UV emission is drastically enhanced by introducing several percent of In into AlGaN. We fabricated single quantum well (SQW) consisting of InxAlyGa1-x-yN quaternary well and barrier, and clearly observed In segregation of sub-micron size from a cathode luminescence (CL) images. The intensity of 320nm-band emission from InAlGaN/InAlGaN QWs were as strong as those of 410nm-band emission from InGaN based QWs, at room temperature. The temperature dependence of photoluminescence (PL) emission for InAlGaN based QWs were much improved in comparison with GaN or AlGaN based QWs. We also grew Mg-doped InxAlyGa1-x-yN quaternary, and obtained hole concentration of 3×1017cm−3 by Hall measurement for high Al content (more than 50%) InxAlyGa1-x-yN quaternary.

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Role of Strain-Induced Microscale Compositional Pulling on Optical Properties of High Al Content AlGaN Quantum Wells for Deep-Ultraviolet LED

Nanoscale Research Letters ◽

10.1186/s11671-022-03652-0 ◽

2022 ◽

Vol 17 (1) ◽

Author(s):

Shiqiang Lu ◽

Zongyan Luo ◽

Jinchai Li ◽

Wei Lin ◽

Hangyang Chen ◽

...

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Tensile Strain ◽

Light Emitting Diode ◽

Formation Enthalpy ◽

Local Variation ◽

Multiple Quantum ◽

Al Content ◽

Deep Ultraviolet ◽

High Al Content

AbstractA systematic study was carried out for strain-induced microscale compositional pulling effect on the structural and optical properties of high Al content AlGaN multiple quantum wells (MQWs). Investigations reveal that a large tensile strain is introduced during the epitaxial growth of AlGaN MQWs, due to the grain boundary formation, coalescence and growth. The presence of this tensile strain results in the microscale inhomogeneous compositional pulling and Ga segregation, which is further confirmed by the lower formation enthalpy of Ga atom than Al atom on AlGaN slab using first principle simulations. The strain-induced microscale compositional pulling leads to an asymmetrical feature of emission spectra and local variation in emission energy of AlGaN MQWs. Because of a stronger three-dimensional carrier localization, the area of Ga segregation shows a higher emission efficiency compared with the intrinsic area of MQWs, which is benefit for fabricating efficient AlGaN-based deep-ultraviolet light-emitting diode.

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