
<!DOCTYPE article
  PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "JATS-journalpublishing1-3.dtd">
<article dtd-version="1.3" article-type="research-article" xml:lang="en"><front xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:c="http://ns.iop.org/namespaces/content" xmlns:date="http://ns.iop.org/namespaces/functions/date" xmlns:m="http://ns.iop.org/namespaces/meta" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><journal-meta><journal-id journal-id-type="publisher-id">sst</journal-id><journal-id journal-id-type="coden">SSTEET</journal-id><journal-title-group><journal-title xml:lang="en">Semiconductor Science and Technology</journal-title><abbrev-journal-title abbrev-type="IOP" xml:lang="en">SST</abbrev-journal-title><abbrev-journal-title abbrev-type="publisher" xml:lang="en">Semicond. Sci. Technol.</abbrev-journal-title></journal-title-group><issn pub-type="ppub">0268-1242</issn><issn pub-type="epub">1361-6641</issn><publisher><publisher-name>IOP Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">sstad575b</article-id><article-id pub-id-type="doi">10.1088/1361-6641/ad575b</article-id><article-id pub-id-type="manuscript">ad575b</article-id><article-id pub-id-type="other">SST-110140.R2</article-id><article-categories><subj-group subj-group-type="display-article-type"><subject>Paper</subject></subj-group><subj-group subj-group-type="special"><compound-subject><compound-subject-part content-type="collection-name">Special Issue on Group III-Nitrides for Next-Generation Optoelectronic Devices</compound-subject-part><compound-subject-part content-type="collection-id">sst-230725-300</compound-subject-part></compound-subject></subj-group></article-categories><title-group><article-title>Microscopy studies of InGaN MQWs overgrown on porosified InGaN superlattice pseudo-substrates</article-title></title-group><contrib-group><contrib contrib-type="author" corresp="yes" xlink:type="simple"><contrib-id authenticated="true" contrib-id-type="orcid">0009-0000-5147-3447</contrib-id><name name-style="western"><surname>Ji</surname><given-names>Yihong</given-names></name><xref ref-type="aff" rid="affiliation01">1</xref><xref ref-type="fn" rid="sstad575bfn1">
                  <sup>*</sup>
               </xref><email>yj335@cam.ac.uk</email></contrib><contrib contrib-type="author" corresp="no" xlink:type="simple"><name name-style="western"><surname>Frentrup</surname><given-names>Martin</given-names></name><xref ref-type="aff" rid="affiliation01">1</xref></contrib><contrib contrib-type="author" corresp="no" xlink:type="simple"><contrib-id authenticated="true" contrib-id-type="orcid">0000-0003-3781-8212</contrib-id><name name-style="western"><surname>Fairclough</surname><given-names>Simon M</given-names></name><xref ref-type="aff" rid="affiliation01">1</xref></contrib><contrib contrib-type="author" corresp="no" xlink:type="simple"><name name-style="western"><surname>Liu</surname><given-names>Yingjun</given-names></name><xref ref-type="aff" rid="affiliation02">2</xref></contrib><contrib contrib-type="author" corresp="no" xlink:type="simple"><name name-style="western"><surname>Zhu</surname><given-names>Tongtong</given-names></name><xref ref-type="aff" rid="affiliation02">2</xref></contrib><contrib contrib-type="author" corresp="no" xlink:type="simple"><contrib-id authenticated="true" contrib-id-type="orcid">0000-0003-0029-3993</contrib-id><name name-style="western"><surname>Oliver</surname><given-names>Rachel A</given-names></name><xref ref-type="aff" rid="affiliation01">1</xref><xref ref-type="aff" rid="affiliation02">2</xref></contrib><aff id="affiliation01">
               <label>1</label>
Department of Materials Science and Metallurgy, <institution xlink:type="simple">University of Cambridge</institution>, Cambridge, <country>United Kingdom</country>
            </aff><aff id="affiliation02">
               <label>2</label>
               <institution xlink:type="simple">Poro Technologies Ltd</institution>, Sawston, Cambridge, <country>United Kingdom</country>
            </aff></contrib-group><author-notes><fn id="sstad575bfn1"><label>3</label><p>Author to whom any correspondence should be addressed.</p></fn></author-notes><pub-date pub-type="ppub"><day>01</day><month>8</month><year>2024</year></pub-date><pub-date pub-type="epub"><day>24</day><month>6</month><year>2024</year></pub-date><pub-date pub-type="open-access"><day>24</day><month>6</month><year>2024</year></pub-date><volume>39</volume><issue>8</issue><elocation-id content-type="artnum">085001</elocation-id><history><date date-type="received"><day>12</day><month>2</month><year>2024</year></date><date date-type="revised"><day>15</day><month>5</month><year>2024</year></date><date date-type="accepted"><day>12</day><month>6</month><year>2024</year></date><date date-type="oa-requested"><day>16</day><month>4</month><year>2024</year></date></history><permissions><copyright-statement>© 2024 The Author(s). Published by IOP Publishing Ltd</copyright-statement><copyright-year>2024</copyright-year><license license-type="cc-by" xlink:href="http://creativecommons.org/licenses/by/4.0" xlink:type="simple"><license-p>
                  <graphic content-type="print" orientation="portrait" position="float" xlink:href="https://content.cld.iop.org/journals/0268-1242/39/8/085001/revision1/sstad575blicense.eps" xlink:type="simple"/>
                  <graphic content-type="online" orientation="portrait" position="float" xlink:href="https://content.cld.iop.org/journals/0268-1242/39/8/085001/revision1/sstad575blicense.gif" xlink:type="simple"/>
Original content from this work may be used under the terms of the <ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">Creative Commons Attribution 4.0 license</ext-link>. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.</license-p></license></permissions><self-uri content-type="pdf" xlink:href="https://content.cld.iop.org/journals/0268-1242/39/8/085001/revision1/sst_39_8_085001.pdf?Expires=1719838341&amp;Signature=DadQNjMtu58zo8-euyRlnYdj3bPwzrYXjO~4W8v34~oadYN-ELZaSXgMAAmrFaao3fjhOJZFkV4VcpJ~aPPMtvUN6JMmnTPsWNRPnj4XB7l-p4hoJ5bNBCY2UzfKI9dlzpSq9Jy3m3jAhMjtkmgr4v-hBsq3t729DZmQcFBFZDLH8eWyIKBHDW1REC-wdhllMPV53FnZBGiYJg09GpkDEIgnbTm2RcPOlyHWjJu3TBhL21isHvzlVVOx4BTi5fujyzvQt2I1O0PIQugXrxX-b9t6E5rpP~yN-Pz1mXHjvO5btPlxMz5mseKYVcmJDvrqKE0Zlfg3fpjFNMSWBjG31Q__&amp;Key-Pair-Id=KL1D8TIY3N7T8" xlink:type="simple"/><abstract><title>Abstract</title><p>In this study, possible origins of small V-pits observed in multiple quantum wells (MQWs) overgrown on as-grown and porosified InGaN superlattice (SL) pseudo-substrates have been investigated. Various cross-sectional transmission microscopy techniques revealed that some of the small V-pits arise from the intersection of threading defects with the sample surface, either as part of dislocation loops or trench defects. Some small V-pits without threading defects are also observed. Energy dispersive x-ray study indicates that the Indium content in the MQWs increases with the averaged porosity of the underlying template, which may either be attributed to a reduced compositional pulling effect or the low thermal conductivity of the porous layer. Furthermore, the porous structure inhibits the glide or extension of the misfit dislocations (MD) within the InGaN SL. The extra strain induced by the higher Indium content and the hindered movement of the MDs combined may explain the observed additional small V-pits present on the MQWs overgrown on the more relaxed templates.</p></abstract><kwd-group kwd-group-type="author"><kwd>InGaN</kwd><kwd>MQWs</kwd><kwd>V-pits</kwd><kwd>microLED</kwd><kwd>porosification</kwd><kwd>TEM</kwd></kwd-group><funding-group><award-group xlink:type="simple"><funding-source xlink:type="simple">Engineering and Physical Sciences Research Council<named-content content-type="funder-id" xlink:type="simple">http://dx.doi.org/10.13039/501100000266</named-content>
               </funding-source><award-id>EP/P024947/1</award-id><award-id>EP/R00661X/1</award-id><award-id>EP/R008779/1</award-id></award-group><award-group xlink:type="simple"><funding-source xlink:type="simple">Innovate UK<named-content content-type="funder-id" xlink:type="simple">http://dx.doi.org/10.13039/501100006041</named-content>
               </funding-source><award-id>107470</award-id></award-group><award-group xlink:type="simple"><funding-source xlink:type="simple">Royal Academy of Engineering<named-content content-type="funder-id" xlink:type="simple">http://dx.doi.org/10.13039/501100000287</named-content>
               </funding-source></award-group></funding-group><counts><page-count count="10"/></counts><custom-meta-group><custom-meta xlink:type="simple"><meta-name>crossmark</meta-name><meta-value>yes</meta-value></custom-meta></custom-meta-group></article-meta></front><back><ack xmlns=""><title>Acknowledgments</title><p>We would like to thank Innovate UK for the financial support within the Collaborative Research and Development scheme ‘<italic toggle="yes">Porous InGaN for Red LEDs (PIRL)</italic>’ (Ref. 107470) and the EPSRC for support through Cambridge Royce facilities Grant EP/P024947/1 and Sir Henry Royce Institute—recurrent grant EP/R00661X/1. We acknowledge the use of the Thermo Fisher Spectra 300 TEM funded by EPSRC under Grant EP/R008779/1. We acknowledge the support of the technical staff Wolfson Electron Microscopy Suite at the University of Cambridge. This work was also supported by the Royal Academy of Engineering under the Chair in Emerging Technologies programme funded by the Department of Science, Innovation and Technology (DSIT).</p></ack></back></article>