Mechanism of nucleation and growth of catalyst-free self-organized GaN columns by MOVPE

Wang, Xue; Li, Shunfeng; Fündling, Sönke; Wehmann, H.-H.; Straßburg, Martin; Lugauer, H.‐J.; Steegmüller, U.; Waag, A.

doi:10.1088/0022-3727/46/20/205101

Cited by 11 publications

(55 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As reported for the self-organized Ga-polar GaN column growth, H 2 as a carrier gas can significantly increase the vertical growth rate due to the strongly increased top surface reaction rate. 19 This means that when the hydrogen passivation on the {11̅ 01} top surfaces is relieved under a low V/III ratio condition, H 2 may promote the deposition rate on these top facets. Consequently, the welldefined columnar structures with {11̅ 00} m-planes are achieved.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Continuous-Flow MOVPE of Ga-Polar GaN Column Arrays and Core–Shell LED Structures

Wang

Mohajerani

et al. 2013

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

Arrays of dislocation free uniform Ga-polar GaN columns have been realized on patterned SiO x /GaN/sapphire templates by metal organic vapor phase epitaxy using a continuous growth mode. The key parameters and the physical principles of growth of Ga-polar GaN three-dimensional columns are identified, and their potential for manipulating the growth process is discussed. High aspect ratio columns have been achieved using silane during the growth, leading to n-type columns. The vertical growth rate increases with increasing silane flow. In a core–shell columnar LED structure, the shells of InGaN/GaN multi quantum wells and p-GaN have been realized on a core of n-doped GaN column. Cathodoluminescence gives insight into the inner structure of these core–shell LED structures.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Continuous-Flow MOVPE of Ga-Polar GaN Column Arrays and Core–Shell LED Structures

Wang

Mohajerani

et al. 2013

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

show abstract

“…As for planar epitaxial growth of GaN, the polarity of nitride NAMs can be directly controlled by the type and/or preparation of the growth substrate 38, 39. Growth on untreated epi‐ready sapphire substrates 22, 40, Ga‐face 1, 28, 29 or Al‐face buffer layers 41, 42 will result in Ga‐face polarity of the NAMs while a sufficiently long nitridation process prior to growth will lead to N‐face polarity on sapphire substrates 3, 23, 39 as does the growth on N‐face GaN substrates 38, 39.…”

Section: Growth and Properties Of The Gan Corementioning

confidence: 99%

Group III nitride core–shell nano‐ and microrods for optoelectronic applications

Mandl

Wang

Schimpke

et al. 2013

Physica Rapid Research Ltrs

Self Cite

View full text Add to dashboard Cite

In the past few years, tremendous progress has been demonstrated on epitaxial growth and processing of group III nitride nano‐ and microrods (NAMs). This has also enabled the fabrication of optoelectronic devices based on NAMs as active elements. However, their efficiency is still far behind the performance of conventional GaN‐based light emitting diodes (LEDs). This Review presents the most recent activities on the growth and processing of NAMs exhibiting a core–shell geometry, i.e. structures which consist of an active region shell layer wrapped around a three‐dimensional (3D) core, which allow for an enormous increase in active area compared to planar technology. The most common growth approaches using metalorganic vapour phase epitaxy are described and evaluated with particular regard to their potential for solid state lighting applications. Examples for the unique properties of 3D NAMs are presented including their excellent crystalline quality. Furthermore, factors limiting the overall performance of 3D core–shell LEDs are revealed and the potential of overcoming these limitations are discussed. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

“…Nitridation of the msapphire surface was observed to be crucial to the inclined angle as well as the growth direction of the GaN NRs. Polarity-selective KOH etching confirmed that both (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) and (1-10-3) GaN NRs are nitrogen-polar. Using pole figure measurements and selective area electron diffraction patterns, the epitaxial relationship between the inclined (11-22) and (1-10-3) GaN NRs and msapphire substrates was systematically demonstrated.…”

mentioning

confidence: 74%

Inclined angle-controlled growth of GaN nanorods onm-sapphire by metal organic chemical vapor deposition without a catalyst

et al. 2015

View full text Add to dashboard Cite

In this study, we have intentionally grown novel types of (11-22)- and (1-10-3)-oriented(3) and self-assembled inclined GaN nanorods (NRs) on (10-10) m-sapphire substrates using metal organic chemical vapor deposition without catalysts and ex situ patterning. Nitridation of the m-sapphire surface was observed to be crucial to the inclined angle as well as the growth direction of the GaN NRs. Polarity-selective KOH etching confirmed that both (11-22) and (1-10-3) GaN NRs are nitrogen-polar. Using pole figure measurements and selective area electron diffraction patterns, the epitaxial relationship between the inclined (11-22) and (1-10-3) GaN NRs and m-sapphire substrates was systematically demonstrated. Furthermore, it was verified that the GaN NRs were single-crystalline wurtzite structures. We observed that stacking fault-related defects were generated during the initial growth stage using high-resolution transmission electron microscopy. The blue-shift of the near band edge (NBE) peak in the inclined angle-controlled GaN NRs can be explained by a band filling effect through carrier saturation of the conduction band, resulting from a high Si-doping concentration; in addition, the decay time of NBE emission in (11-22)- and (1-10-3)-oriented NRs was much shorter than that of stacking fault-related emission. These results suggest that defect-free inclined GaN NRs can be grown on m-sapphire without ex situ treatment.

show abstract

Mechanism of nucleation and growth of catalyst-free self-organized GaN columns by MOVPE

Cited by 11 publications

References 31 publications

Continuous-Flow MOVPE of Ga-Polar GaN Column Arrays and Core–Shell LED Structures

Continuous-Flow MOVPE of Ga-Polar GaN Column Arrays and Core–Shell LED Structures

Group III nitride core–shell nano‐ and microrods for optoelectronic applications

Inclined angle-controlled growth of GaN nanorods onm-sapphire by metal organic chemical vapor deposition without a catalyst

Contact Info

Product

Resources

About