Optical properties of AlGaN quantum well structures
AlN or AlGaN is very attractive material for the application to ultraviolet (UV) laser diodes (LDs), light-emitting diodes (LEDs) or photo detectors, because the direct transition energy can be adjusted between 6.2 eV (AlN) and 3.4 eV (GaN). The authors 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, they show the PL properties of high Al content AlGaN bulk (Al content: 85--95%) emitting from near band-edge. The authors systematically investigated the PL properties of AlGaN-MQWs consisting of wide bandgap AlGaN (Al content: 53--100%) barrier. They obtained efficient PL emission of 234 and 245 nm from AlN/Al{sub 0.18}Ga{sub 0.82}N and Al{sub 0.8}Ga{sub 0.2}N/Al{sub 0.18}Ga{sub 0.82}N 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. The authors found that the most efficient PL is obtained at around 240 nm from AlGaN MQWs with Al{sub 0.8}Ga{sub 0.2}N barriers. Also, they found that the PL from AlGaN MQW is as efficient as that of InGaN QWs at 77 K.
- Research Organization:
- Inst. of Physical and Chemical Research, Wako, Saitama (JP)
- OSTI ID:
- 20104606
- Country of Publication:
- United States
- Language:
- English
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