Peculiarities of extended defect system in III-nitrides with different degrees of order of mosaic structure

Ankudinov, A. B.; Besyul’kin, A. I.; Колмаков, А. Г.; Lundin, W. V.; Ратников, В. В.; Shmidt, N. M.; Ситникова, А. А.; Titkov, A. N.; Usikov, A.; Yakimov, E. B.; Заварин, Е. Е.; Zolotareva, R. V.

doi:10.1016/j.physb.2003.09.036

Cited by 18 publications

(13 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recently [1,2], it has been demonstrated that the value of ∆ can be evaluated after the treatment of a digital ensemble, corresponding to the AFM surface view, using the multifractal analysis. The comparative investigations of structural, electrical and optical properties of GaN epilayers with different ∆ [3,4] show that abstract parameter ∆ reflects real volume properties of EDS. For the poor-ordered epilayers with.…”

Section: Introductionmentioning

confidence: 99%

“…For epilayers with intermediate value of ∆, both types of EDS relaxation were observed. It was established [3,4], that the domain dislocation boundaries determined the high density of unstable centers, the low diffusion length and mobility of carriers, and the persistence photoconductivity. Proceeding from these results we used ∆ for classification LES and we investigated optical properties of LES with different ∆ to clarify the influence of the peculiarities of EDS on the efficiency of the LES luminescence.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Surface control of light‐emitting structures based on III‐nitrides

Besyul’kin

Карташова

Колмаков

et al. 2005

phys. stat. sol. (c)

View full text Add to dashboard Cite

The results on surface control of light-emitting structures (LES) based on MQW InGaN/GaN grown by MOCVD on (0001) sapphire substrates have been presented. For these purposes, the treatment of atomicforce-microscopy data by multifractal analyses has been applied. It was shown, that multifractal parameter (the degree of order of mosaic structure, ∆) reflects the peculiarities of the extended defect system (EDS), including mosaic structure and high density of dislocations, and correlates with the volume structural, electrical and optical properties of LES. Depending on ∆, EDS relaxes with formation of either the domain dilatation boundaries or numerous domain dislocation boundaries and these structural peculiarities influence essentially the shape of photo-and electroluminescence spectra, delayed spectra and the values of external quantum efficency. The surface control using ∆ can be applied to optimize the properties of LES and the process of their creation.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Surface control of light‐emitting structures based on III‐nitrides

Besyul’kin

Карташова

Колмаков

et al. 2005

phys. stat. sol. (c)

View full text Add to dashboard Cite

show abstract

“…However, the extended defect system in III-nitrides besides the threading dislocations includes also the typical for these materials mosaic structure, ordering of which could depend essentially on the defect system relaxation. For the well-ordered mosaic structures the defect relaxation occurs via the coherent concordance of mosaic structure domains with a formation of dilatation boundaries, while for the less-ordered mosaic structures the defect system relaxation occurs via the formation of numerous dislocated domain boundaries, the edge dislocation density in which exceeds essentially that of screw threading dislocations [1]. As shown in [2,3], the close correlation between mosaic structure ordering and the surface roughness allows the quantitative characterization of mosaic structure ordering by the multifractal analysis based on the atomic force microscopy data.…”

mentioning

confidence: 99%

Comparative study of quantum efficiency of blue LED with different nanostructural arrangement

Greshnov

Chernyakov

Ber

et al. 2007

Phys. Status Solidi (c)

View full text Add to dashboard Cite

Current-voltage characteristics and quantum efficiency dependence on injected current for blue light emitting diodes with different nanostructural arrangement were studied. The Electron Beam Induced Current (EBIC) technique was used to monitor the hole recombination inside the quantum wells and to reveal the lateral inhomogeneities in the recombination velocity. The bright EBIC contrast associated with extended defects was revealed. This contrast was explained by a formation of channels with enhanced conductivity near the extended defects penetrating the active device region. 1 Introduction In spite of essential progress in the multiple quantum well (MQW) InGaN/GaN blue light emitting diodes (LED) technology, the reasons for rather high values of external quantum efficiency (QE) at low injection currents and its decrease at injection currents larger than 100 mA are not clear yet. The major part of investigations in this field dealt with studies of radiation recombination efficiency dependence on the In inhomogeneous distribution into InGaN layers leading to a quantum dot formation, on the layer thickness variation in MQW InGaN/GaN structures, on the polarization field and on dislocation density. However, the extended defect system in III-nitrides besides the threading dislocations includes also the typical for these materials mosaic structure, ordering of which could depend essentially on the defect system relaxation. For the well-ordered mosaic structures the defect relaxation occurs via the coherent concordance of mosaic structure domains with a formation of dilatation boundaries, while for the less-ordered mosaic structures the defect system relaxation occurs via the formation of numerous dislocated domain boundaries, the edge dislocation density in which exceeds essentially that of screw threading dislocations [1]. As shown in [2,3], the close correlation between mosaic structure ordering and the surface roughness allows the quantitative characterization of mosaic structure ordering by the multifractal analysis based on the atomic force microscopy data. However, in spite of essential ordering effect on the electrical and optical properties of hexagonal III-nitrides, the detail study of QE dependence in the III-nitride based LEDs on the nanostructural arrangement (NA) determined by the extended defect system relaxation was not carried out up to now.In the present work a comparative study of LEDs with the different NA has been carried out. The main purpose of this study is revealing a correlation between the NA and the electroluminescence efficiency and current-voltage (I -V) characteristics. The Electron Beam Induced Current (EBIC) technique

show abstract

“…It is well known from material science that the migration of dislocations in such system is practically impossible. Resent experimental data for GaN-based blue LEDs confirmed this conclusion [2].Our previous results of structural, optical and electrical properties studies [6,7] allow to suppose that structural disorder determined by the extended defect system relaxation and related with peculiarities of domains coalescence can be one of the degradation reason.…”

Section: Resultsmentioning

confidence: 62%

Degradation of blue LEDs related to structural disorder

Kamanin

Колмаков

Kop’ev

et al. 2006

Phys. Status Solidi (c)

View full text Add to dashboard Cite

The degradation of blue light emitting diodes (LEDs) with different structural disorder based on MQW InGaN/GaN grown by MOCVD on sapphire has been investigated. New approach to analyze the degradation has been used. It takes into account the structural disorder determined by the extended defect system relaxation and related with poor coalescence of the mosaic structure domains. The results obtained leads to assumption that the migration and segregations of Ga on domain dislocation boundaries of the mosaic structure and the change of energy activation of Mg related centers are important reasons of degradation for all types of LEDs The fastest degradation for poor ordered LEDs was observed.

show abstract

Peculiarities of extended defect system in III-nitrides with different degrees of order of mosaic structure

Cited by 18 publications

References 10 publications

Surface control of light‐emitting structures based on III‐nitrides

Surface control of light‐emitting structures based on III‐nitrides

Comparative study of quantum efficiency of blue LED with different nanostructural arrangement

Degradation of blue LEDs related to structural disorder

Contact Info

Product

Resources

About