Electronic Energy Levels in Group-III Nitrides

Palmer, D.W.

doi:10.1016/b978-0-44-453153-7.00114-0

Cited by 13 publications

(6 citation statements)

References 198 publications

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“…The traps presented in Fig. 2 and 3 are quite common for undoped n-GaN films grown by HVPE, MOCVD or MBE (Lee et al, 2012;Polyakov et al, 2011;Palmer, 2011;Pearton et al, 2013). Deep hole traps spectra obtained for group 1 and 2 samples with intrinsic optical excitation (high-power 365-nm LED source) are presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

Deep Traps Spectra in Undoped Gan Films Grown by Hydride Vapor Phase Epitaxy Under Various Conditions

Polyakov¹,

Smirnov²,

Говорков³

et al. 2014

American Journal of Applied Sciences

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Decreasing the residual donors density and deep traps spectra densities in undoped GaN films grown by Hydride Vapor Phase Epitaxy (HVPE) is very important for promoting the use of such material in highvoltage/high-power rectifiers, radiation detectors. In this study we studied the effects of changing the growth temperature of undoped HVPE GaN films on these properties. The two groups of undoped GaN HVPE samples analyzed in this study were grown at growth temperature being either 850ºC or 950ºC. Measurements by means of Capacitance-Voltage (C-V) profiling, deep levels transient spectroscopy, Micro Cathode Luminescence (MCL) spectroscopy and imaging and by Electron Beam Induced Current (EBIC) showed a much lower density of residual donors (by almost two orders of magnitude), of deep electron traps and hole traps (by about an order of magnitude) and considerably (about 1.5 times) longer diffusion length of charge carriers in the films grown at 850ºC compared to samples prepared at 950ºC. The data obtained indicate that there is an optimal reduced growth temperature (close to 850ºC) resulting in lower concentration of shallow donors and deep traps while still preserving the high crystalline quality of the layer. This is of paramount importance for device applications of HVPE grown undoped GaN films.

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Section: Resultsmentioning

confidence: 99%

Deep Traps Spectra in Undoped Gan Films Grown by Hydride Vapor Phase Epitaxy Under Various Conditions

Polyakov¹,

Smirnov²,

Говорков³

et al. 2014

American Journal of Applied Sciences

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“…Aluminum nitride (AlN) is luminescent wide band gap solid state material with wurtzite crystalline structure possessing a lot of excellent properties such as high thermal stability and hardness, high thermal conductivity and low electrical conductivity [1,2]. Different forms of AlN material are known including bulk materials such as the single crystals and ceramics, and nanosize ones (nano particles, nanorods, nanotubes etc.).…”

Section: Uminescementioning

confidence: 99%

Luminescent AlN:Mn nanoparticles for optical imaging of biological materials

Bērziņa¹,

Trinkler²,

Korsaks³

et al. 2020

Biophysical Bulletin

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Background: Elaboration of new luminescent nanomaterials for imaging of biological materials including cells of living organisms and their parts is highly actual. These materials must meet a number of requirements such as low toxicity, inherence of intensive luminescence, low costs of raw material and symple synthesis methods. AlN nanopowder is one of such prospective materials fitting the above requirements. Our long time investigations on spectral characteristics for III group element nitrides allows chose of doped AlN nanopowder as prospective candidate for developing of luminescent markers for imaging of biological materials. Objectives: The aim of the present study is spectral characterization of AlN nanopowder doped with Mn and evaluation of its use as luminescent marker for biological materials. Materials and methods: AlN nanopowder with average size of polycrystalline grains of 60 nm and the same doped with Mn were sythesized in Institue of Inorganic Chemistry, Riga Technical University. Photoluminescence and its excitation spectra of the materials were studied at room temperature using a self-made set-up. Results: It was found that in undoped AlN nanopowder at room temperature luminescence of native defects forms a wide and complex band peaking at 415 nm. This blue luminescence can be excited with ultraviolet light from two spectral regions around 315–340 nm and 260 nm. Two luminescence mechanisms are proposed dependent on the spectral region of exciting light. The first of them results in the intra-center luminescence, but the second one is recombination luminescence. Incorporation of Mn atoms in the crystalline lattice of AlN nanopowder forming AlN:Mn NP results in appearance of intensive red luminescence at 600 nm, which can be excited with light from two excitation bands at 260 and 480 nm. Two mechanisms responsible for an appearence of the red luminescence of Mn are proposed. They are the intra-center luminescence and recombination luminescence mechanisms. In this case the red Mn luminiscence prevails and the blue luminescence characterizing the host material has not been observed. Conclusion: AlN nanopowder doped with Mn atoms is a prospective material for use as luminescent marker for imaging of biological materials. Properties of this material are in a good agreement with the main requirements obligated to biological materials: i) AlN NP has low toxicity; ii) AlN:Mn NP possesses intensive red luminescence at 600 nm, which can be excited either with the ultraviolet light around 260 nm or with visible light around 480 nm; iii) it is relatively cheep material and it can be synthesized using simple synthesis methods.

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“…unintentional incorporation of impurities like oxygen, hydrogen, iron, carbon etc.). 6 Another category of defects are surface and interface states that occur at the hetero-interface boundaries. 7 When these defects become electrically active i.e.…”

Section: Introductionmentioning

confidence: 99%

Defects in GaN based transistors

et al. 2014

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Electrically active defects in AlGaN/GaN high electron mobility transistors (HEMTs) are the source of intense study due to their linkage to the mechanisms for GaN HEMT degradation upon a variety of stress conditions. The ability to directly characterize traps and identify their sources in GaN HEMTs is challenging, however, and this is due to a combination of the large bandgap of these materials and the complex electrostatics present in these device structures. Furthermore, the targeted extreme operating conditions intended for GaN HEMTs, whether designed for RF or power applications, greatly exacerbate the ability to identify those defects that are most relevant to device degradation under actual operation. Over the past few years, however, we have developed several electronic defect characterization methods based on deep level optical spectroscopy (DLOS) and thermally-based deep level transient spectroscopy (DLTS), which have been adapted from basic studies of defects in GaN and AlGaN to become applicable to working HEMTs. These so-called constant drain current (CID) DLOS/DLTS methods are able to directly provide individual trap concentrations and energy levels for traps that may exist throughout the AlGaN/GaN HEMT bandgap, and can discern between traps under the gate or in the transistor access regions. This talk will first review the CID-DLOS/DLTS methodology and then will focus on the application of these methods to stressed and un-stressed AlGaN/GaN HEMTs. Direct correlations of the formation of several specific traps are made with a variety of HEMT degradation mechanisms induced by stresses that include RF, DC and also proton irradiation

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Electronic Energy Levels in Group-III Nitrides

Cited by 13 publications

References 198 publications

Deep Traps Spectra in Undoped Gan Films Grown by Hydride Vapor Phase Epitaxy Under Various Conditions

Deep Traps Spectra in Undoped Gan Films Grown by Hydride Vapor Phase Epitaxy Under Various Conditions

Luminescent AlN:Mn nanoparticles for optical imaging of biological materials

Defects in GaN based transistors

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