Show simple item record

dc.contributor.authorGao, Y.en_US
dc.contributor.authorLi, M.en_US
dc.contributor.authorDelikanli S.en_US
dc.contributor.authorZheng, H.en_US
dc.contributor.authorLiu, B.en_US
dc.contributor.authorDang C.en_US
dc.contributor.authorSum, T. C.en_US
dc.contributor.authorDemir, Hilmi Volkanen_US
dc.date.accessioned2019-02-21T16:02:50Zen_US
dc.date.available2019-02-21T16:02:50Zen_US
dc.date.issued2018en_US
dc.identifier.issn2040-3364en_US
dc.identifier.urihttp://hdl.handle.net/11693/50048en_US
dc.description.abstractColloidal type-II heterostructures are believed to be a promising solution-processed gain medium given their spatially separated electrons and holes for the suppression of Auger recombination and their wider emission tuning range from the visible to near-infrared region. Amplified spontaneous emission (ASE) was achieved from colloidal type-II core/shell nanocrystals several years ago. However, due to the limited charge-transfer (CT) interfacial states and minimal overlap of electron and hole wave functions, the ASE threshold has still been very high. Herein, we achieved ASE through type-II recombination at a lower threshold using CdSe/CdSeTe core/alloyed-crown nanoplatelets. Random lasing was also demonstrated in the film of these nanoplatelets under sub-ns laser-pumping. Through a detailed carrier dynamics investigation using femtosecond transient absorption, steady state, and time-resolved photoluminescence (PL) spectroscopies, we confirmed the type-II band alignment, and found that compared with normal CdSe/CdTe core/crown nanoplatelets (where no ASE/lasing was observed), CdSe/CdSeTe core/alloyed-crown nanoplatelets had a much higher PL quantum yield (75% vs. 31%), a ∼5-fold larger density of type-II charge-transfer states, a faster carrier transfer to interfaces (0.32 ps vs. 0.61 ps) and a slower Auger recombination lifetime (360 ps vs. 160 ps). Compared with CdSe/CdTe nanoplatelets, their counterparts with an alloyed crown boast a promoted charge transfer process, higher luminescence quantum yield, and smaller Auger rate, which results in their excellent application potential in solution-processed lasers and light-emitting devices.en_US
dc.description.sponsorshipThe authors are thankful for financial support from the Singapore National Research Foundation under NRF-NRFI2016-08. The electron microscopy imaging was performed at the Facility for Analysis, Characterization, Testing, and Simulation (FACTS) at Nanyang Technological University, Singapore. T. C. S. also acknowledges financial support from the Ministry of Education Academic Research Fund Tier 1 grants RG101/15 and RG173/16, and Tier 2 grants MOE2015-T2-2-015 and MOE2016-T2-1-034; and from the Singapore National Research Foundation through the Competitive Research Program NRF-CRP14-2014-03. In addition, C. D. acknowledges the NTU start-up grant (M40810482).en_US
dc.language.isoEnglishen_US
dc.source.titleNanoscaleen_US
dc.relation.isversionofhttps://doi.org/10.1039/c8nr01838cen_US
dc.titleLow-threshold lasing from colloidal CdSe/CdSeTe core/alloyed-crown type-II heteronanoplateletsen_US
dc.typeArticleen_US
dc.departmentInstitute of Materials Science and Nanotechnology (UNAM)en_US
dc.citation.spage9466en_US
dc.citation.epage9475en_US
dc.citation.volumeNumber10en_US
dc.citation.issueNumber20en_US
dc.relation.projectNational Research Foundation Singapore, NRF: NRF-NRFI2016-08 - Nantong University, NTU: M40810482 - MOE2015-T2-2-015 - NRF-CRP14-2014-03 - MOE2016-T2-1-034 - RG101/15 - RG173/16 - Nanyang Technological University, NTUen_US
dc.identifier.doi10.1039/c8nr01838cen_US
dc.publisherRoyal Society of Chemistryen_US
dc.contributor.bilkentauthorDemir, Hilmi Volkan
dc.identifier.eissn2040-3372en_US
buir.contributor.orcidDemir, Hilmi Volkan|0000-0003-1793-112Xen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record