| 1. |
- Eriksson, Martin O., et al.
(författare)
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Recombination processes in Mg doped wurtzite InN films with p- and n-type conductivity
- 2019
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Ingår i: AIP Advances. - : AMER INST PHYSICS. - 2158-3226. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Obtaining high quality, wurtzite InN films with p-type conductivity is a challenge, and there is limited information about the photoluminescence (PL) characteristics of such films. In this study, we present a comprehensive PL study and discuss in detail the recombination processes in Mg-doped InN films with varying Mg concentrations. We find that at low Mg-doping of 1x10(18) cm(-3), which yields p-type conductivity, the PL in InN is spatially inhomogeneous. The latter is suggested to be associated with the presence of n-type pockets, displaying photoluminescence at 0.73 eV involving electrons at the Fermi edge above the conduction band edge. Increasing the Mg concentration to 2.9x10(19) cm(-3) in p-type InN yields strong and spatially uniform photoluminescence at 0.62 eV and 0.68 eV visible all the way to room temperature, indicating homogeneous p-type conductivity. An acceptor binding energy of 64 meV is determined for the Mg acceptor. Further increase of the Mg concentration to 1.8x10(20) cm(-3) leads to switching conductivity back to n-type. The PL spectra in this highly doped sample reveal only the emission related to the Mg acceptor (at 0.61 eV). In the low-energy tail of the emission, the multiple peaks observed at 0.54 - 0.58 eV are suggested to originate from recombination of carriers localized at stacking faults. (C) 2019 Author(s).
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| 2. |
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| 3. |
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| 4. |
- Ochalski, T.J., et al.
(författare)
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Optical study of AlGaN/GaN based HEMT structures
- 2005
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - 1610-1634 .- 1610-1642. ; 2, s. 2791-2794
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Ochalski, TJ, et al.
(författare)
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Optical study of AlGaN/GaN based HEMT structures grown on sapphire and SiC
- 2005
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Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 202:7, s. 1300-1307
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Tidskriftsartikel (refereegranskat)abstract
- A detailed photoluminescence (PL), time-resolved photoluminescence (TRPL), and photoreflectance (PR) analysis of AlGaN/GaN heterostructures grown on different substrates: sapphire and silicon carbide (SiC) is presented in this paper. The properties of high electron mobility transistors (HEMTs) based on AlGaN/GaN structures are strongly dependent on the quality of the AlxGa1-xN top layer. We have examined a number of samples, grown on sapphire, in which the thicknesses of the Al0.3Ga0.7N layers vary from 18 to 75 nm. Room temperature PL under pulsed 266 nm excitation allowed for determination of the AI content in the examined thin AlGaN layers. Time-resolved PL measured at 1.6 K showed huge difference in the emission dynamics for different Al0.3Ga0.7N layer thicknesses. We observed an enormous increase of the emission decay time above the critical thickness of the AlGaN layer. PR spectra (associated with the GaN main layer) measured on AlGaN/GaN systems are discussed in terms of the thickness of the capping layer. The PR modulated by a high power 266 nm pulsed laser measured on a transistor structure exhibited an additional feature placed between signals related to the GaN and AlGaN layers, respectively. Such a transition is possible to monitor only for the structures of the best quality and is accordingly observable only on samples grown on SiC. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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| 6. |
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| 7. |
- Zhuravlev, K.S., et al.
(författare)
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Microphotoluminescence of GaN/AlN quantum dots grown by MBE
- 2006
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - 1610-1634 .- 1610-1642. ; 3, s. 2048-2051
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Tidskriftsartikel (refereegranskat)abstract
- Presented at: The 6th International Conference on Nitride Semiconductors (ICNS6), Bremen, Germany, Aug 28-Sept 2, 2005
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