{"id":290,"date":"2022-01-05T14:21:56","date_gmt":"2022-01-05T06:21:56","guid":{"rendered":"https:\/\/www.eee.hku.hk\/microLED\/?p=290"},"modified":"2022-01-05T14:21:58","modified_gmt":"2022-01-05T06:21:58","slug":"strain-induced-spectral-red-shifting-from-nanoscale-frustum-arrays-fabricated-over-ingan-gan-quantum-wells-for-light-emitting-applications","status":"publish","type":"post","link":"https:\/\/www.eee.hku.hk\/microLED\/strain-induced-spectral-red-shifting-from-nanoscale-frustum-arrays-fabricated-over-ingan-gan-quantum-wells-for-light-emitting-applications\/","title":{"rendered":"Strain-Induced Spectral Red-Shifting from Nanoscale Frustum Arrays Fabricated over InGaN\/GaN Quantum Wells for Light-Emitting Applications"},"content":{"rendered":"\n

– WY Fu, and HW Choi<\/em><\/p>\n\n\n\n

\"\"
Calculated average spectral red-shifts from 3 samples induced by the inverted nanoconical frustums by deducing the change in PL emission peak wavelength via Gaussian fitting. Note that the reverse-tapering angle also slightly changes with the etch depth, as demonstrated by the 45-degree-tilted SEM images in the inset. Above the graph is a cross-sectional TEM image of the sample taken along the [11 2\u03050] zone axis, sized to correspond to the\u00a0x<\/em>-axis of the graph (The scale bar is 50 nm).<\/figcaption><\/figure>\n\n\n\n

ACS Applied Nano Materials, vol. 4, 1, pp. 666-672 (2021)<\/em><\/strong><\/p>\n\n\n\n

While spectral blue-shifting caused by nanostructuring of InGaN\/GaN quantum wells has been widely reported for altering the emission color of light-emitting diodes, the same cannot be said for spectral red-shifting. It is well-known that nanostructuring of the quantum wells gives rise to relaxation of the strain incurred in the quantum wells, reducing the quantum confined stark effect with a consequence of spectral shifting to shorter wavelengths. In this report, we demonstrate a nanostructure configuration that produces the opposite effect, spectral red-shifting, by increasing the strain in the quantum wells through the formation of an inverted nanoconical-frustum array over the quantum wells, without allowing the nanostructures to penetrate through the quantum wells. Under such conditions, spectral red-shifting of the photoluminescence spectrum can be observed, consistent with the prediction of strain induction in the quantum wells by molecular dynamics simulations. Experimentally, spectral red-shift of the photoluminescence spectrum by up to 7.6 nm has been observed, when the proposed nanostructures are fabricated on InGaN\/GaN quantum wells grown on a c-plane sapphire substrate with a nominal emission wavelength of \u223c560 nm.<\/p>\n\n\n\n

DOI: <\/a><\/a><\/a><\/a><\/a><\/a>10.1021\/acsanm.0c02939<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

– WY Fu, and HW Choi ACS Applied Nano Materials, vol. 4, 1, pp. 666-672 (2021) While spectral blue-shifting caused by nanostructuring of InGaN\/GaN quantum…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[7,4,8,10,11],"class_list":["post-290","post","type-post","status-publish","format-standard","hentry","category-publications","tag-color-tuning","tag-microled","tag-monolithic","tag-nanosphere","tag-nanostructure"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/290","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/comments?post=290"}],"version-history":[{"count":1,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/290\/revisions"}],"predecessor-version":[{"id":292,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/posts\/290\/revisions\/292"}],"wp:attachment":[{"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/media?parent=290"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/categories?post=290"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.eee.hku.hk\/microLED\/wp-json\/wp\/v2\/tags?post=290"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}