Homoepitaxy and Photoluminescence Properties of (0001) AlN

Funato, Mitsuru; Matsuda, Kazuhisa; Banal, Ryan G.; Ishii, Ryota; Kawakami, Yoichi

doi:10.1143/apex.5.082001

Cited by 52 publications

(53 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This transition is identified as a bound exciton (presumably to a neutral donor) from temperature dependent luminescence experiments. Note that this donor bound exciton is not visible for E k c as already found by Funato et al 13 We can follow the transition energies of C 1 and C 5 exciton states in temperature dependent spectra and find a perfect agreement for the C 1 exciton energy obtained from luminescence and ellipsometry data (Fig. 4) further corroborating our identification.…”

Section: -2supporting

confidence: 90%

See 1 more Smart Citation

Negative spin-exchange splitting in the exciton fine structure of AlN

Feneberg

Romero

Neuschl

et al. 2013

Applied Physics Letters

View full text Add to dashboard Cite

Tuning energy levels in magnesium modified Alq3 J. Appl. Phys. 109, 083541 (2011) Disorder-induced exciton localization and violation of optical selection rules in supramolecular nanotubes J. Chem. Phys. 134, 114507 (2011) Exciton-polariton transmission in quantum dot waveguides and a new transmission path due to thermal relaxation J. Chem. Phys. 134, 044108 (2011) Double excitations in correlated systems: A many-body approach J. Chem. Phys. 134, 034115 (2011) Additional information on Appl. Phys. Lett.

show abstract

Section: -2supporting

confidence: 90%

“…On high quality (0001) c-oriented homoepitaxial layers, an energy of 6.040 eV is reported at low temperature for the lowest free exciton transition, [11][12][13] while on off-oriented a)…”

mentioning

confidence: 99%

Negative spin-exchange splitting in the exciton fine structure of AlN

Feneberg

Romero

Neuschl

et al. 2013

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Only recently, homoepitaxial AlN layers of good crystal quality became available allowing the proper identification of single bound excitonic emission bands. 12,13 However, for the mostly present donor silicon (Si), there is no agreement on the ionization energy. There is an ongoing discussion, whether Si Al undergoes a strong lattice relaxation and forms a deep DX center, where the dopant atom captures a second electron.…”

mentioning

confidence: 99%

Direct determination of the silicon donor ionization energy in homoepitaxial AlN from photoluminescence two-electron transitions

Neuschl

Thonke

Feneberg

et al. 2013

Applied Physics Letters

View full text Add to dashboard Cite

We report on the identification of a two-electron transition for the shallow donor silicon in homoepitaxial aluminum nitride (AlN). One c-oriented sample was analyzed by low temperature photoluminescence spectroscopy on multiple excitation spots. We find a unique correlation of one single emission band, 76.6 meV below the free excitonic emission, with the luminescence of excitons bound to neutral silicon proving the identity as a two-electron transition. The assignment is confirmed by temperature dependent photoluminescence investigations. We find a donor ionization energy of ð63:5 6 1:5Þ meV for silicon in AlN. V C 2013 AIP Publishing LLC.Recent interest in light emitting devices operating in the deep UV spectral region 1 is due to promising applications such as the deactivation of microorganisms by exposure to light with short wavelengths. Several research groups are working on light emitting diodes (LEDs) based on aluminum gallium nitride (AlGaN) fabricated on foreign substrates such as sapphire 2-4 or silicon carbide. 5 As a consequence, these structures suffer from high defect densities due to the lattice and thermal expansion coefficient mismatch between the substrate material and the epitaxial film, directly degrading the efficiency of the device. 6 One approach is to deposit the diode layer, with high Al content, directly on an AlN single crystal. This kind of substrate is promising for an improvement of the crystal quality, 7,8 and recently, well operating LEDs 9 and lasers 10,11 have been presented. Nevertheless, many fundamental properties such as the exact electronic structure for typical dopants are not known. Only recently, homoepitaxial AlN layers of good crystal quality became available allowing the proper identification of single bound excitonic emission bands. 12,13 However, for the mostly present donor silicon (Si), there is no agreement on the ionization energy. There is an ongoing discussion, whether Si Al undergoes a strong lattice relaxation and forms a deep DX center, where the dopant atom captures a second electron. Several theoretical studies predict DX center formation for Si Al , 14,15 whereas others find silicon to be a shallow donor in wurtzite AlN. 16,17 Experimentally, the majority of studies shows n-type conductivity after silicon doping, 18-24 although they find very different values for the ionization energy ranging from 86 to 570 meV. On the other hand, there are two detailed reports about DX center formation found by spectrally resolved photoconductivity and electron paramagnetic resonance. 25,26 In this letter, we present a detailed investigation of a homoepitaxially grown wurtzite AlN layer by means of temperature dependent photoluminescence (PL) spectroscopy. Exposure at multiple excitation spots and the temperature dependent behavior of the emission bands observed allow for an identification of a two-electron transition with shallow silicon donors involved. We further discuss the presented results in the framework of possible DX center formation.The sample under investigat...

show abstract

“…After that, a 200 nm Si-doped Al x Ga 1-x N layer was grown on the high-Al-mole-fraction AlGaN layers, and 75-pairs MQWs consisting of 1.3-1.5 nm Al y Ga 1-y N wells and 7 nm Al x Ga 1-x N barriers were grown on the Sidoped Al x Ga 1-x N layer [10]. For structure (b), owing to improve the quality of the surface of AlN layer [11,12], an AlN interlayer with growth temperature at 1450 o C was inserted between AlN/sapphire substrate and two-high-Almole-fraction AlGaN layer. For structure (c), an Alcomposition-graded AlGaN layer was grown after an AlN interlayer at 1450 o C with decreasing Al composition by lowering the temperature gradually from the growth temperature of AlN.…”

Section: Methodsmentioning

confidence: 99%

Fabrication of AlGaN multiple quantum wells on sapphire with lattice‐relaxation layer

Nakahama

Fukuyo

Miyake

et al. 2015

physica status solidi c

View full text Add to dashboard Cite

The influences of three types of lattice‐relaxation layer between AlGaN multiple quantum wells (MQWs) and AlN layer on sapphire substrate were investigated. For structure (a), two‐high‐Al‐mole‐fraction AlGaN layers grown at 1170 °C was prepared. For structure (b), an AlN interlayer with growth temperature at 1450 °C was inserted between AlN/sapphire substrate and two‐high‐Al‐mole‐fraction AlGaN layer. For structure (c), an Al‐composition‐graded AlGaN layer with decreasing Al composition was grown after an AlN interlayer at 1450 °C by lowering the temperature gradually from the growth temperature of AlN. The narrowest rocking curve X‐ray diffraction at AlGaN MQWs occurs while using structure (b) as lattice‐relaxation layer. The highest emission intensity of cathodoluminescence from AlGaN MQWs at room temperature was also shown by using structure (b). The ratio of integrated intensity of spectra at 300 K and 10 K (I300K/I10K) is 58%. High temperature AlN films as lattice‐relaxation layer improved the crystal quality and emission intensity in AlGaN MQWs. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Homoepitaxy and Photoluminescence Properties of (0001) AlN

Cited by 52 publications

References 24 publications

Negative spin-exchange splitting in the exciton fine structure of AlN

Negative spin-exchange splitting in the exciton fine structure of AlN

Direct determination of the silicon donor ionization energy in homoepitaxial AlN from photoluminescence two-electron transitions

Fabrication of AlGaN multiple quantum wells on sapphire with lattice‐relaxation layer

Contact Info

Product

Resources

About