{"id":1094,"date":"2013-07-11T15:43:27","date_gmt":"2013-07-11T15:43:27","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/?p=1094"},"modified":"2013-07-25T18:31:26","modified_gmt":"2013-07-25T18:31:26","slug":"binary-nanoparticle-superlattices-formed-from-highly-luminescent-core-shell-quantum-dots-and-their-photoluminescence-properties","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/binary-nanoparticle-superlattices-formed-from-highly-luminescent-core-shell-quantum-dots-and-their-photoluminescence-properties\/","title":{"rendered":"Binary Nanoparticle Superlattices Formed from Highly Luminescent Core-Shell Quantum Dots and Their Photoluminescence Properties"},"content":{"rendered":"
\"Figure<\/a>

Figure 1. Large-area (1.5- x 1.5-cm Si\/SiO2 substrate) binary nanocrystal superlattices (BNSLs) assembled from 8-nm CdSe\/ZnS and 4-nm PbS\/CdS core-shell QDs. (a) Fluorescence microscope image (1000x, 595-nm band filter) of BNSLs showing an average grain size of 3.2 um. (b) False color high-resolution transmission microscope (HRTEM) image and small-angle electron diffraction (CL 200 cm) pattern obtained from a single BNSL domain showing a formation of a cub-AB13 structure.<\/p><\/div>\n

Colloidal semiconductor nanocrystals or quantum dots (QDs) offer size-tunable absorption and luminescence spectra, permitting a broad range of applications in optoelectronics and biomedical imaging. Advances in colloidal synthesis enable the preparation of monodispersed QDs, which can be further used as building blocks to direct self-assembly into closely packed superlattices with well-defined spatial coordination. Superlattices can also be formed from two different materials of QDs, often referred to as binary nanocrystal superlattices (BNSLs)[1<\/a>]<\/sup>,[2<\/a>]<\/sup>, providing an excellent materials platform to explore unique photophysical properties arising from electronic and optical interactions between two components.<\/p>\n

In this work, we report for the first time BNSLs assembled from highly luminescent 8-nm CdSe\/ZnS and 4-nm PbS\/CdS core\/shell QDs. Single superlattice domains with an average size of 3.2 \u03bcm show formation of cub<\/i>-AB13<\/sub> structures as confirmed by scanning electron microscopy, transmission electron microscopy, selective area electron diffraction, and structural modeling (Figure 1). We characterized these BNSLs optically via micro-photoluminescence spectroscopy of single superlattice domains formed on a Si\/SiO2<\/sub> substrate. We probed resonant energy transfer from CdSe\/ZnS to PbS\/CdS QDs, enabled by the spectral overlap of their emission and absorption spectra, respectively. A combination of spectral and time-resolved dynamics was used to elucidate differences in energy transfer between amorphous and ordered superlattice arrays; these differences will be further discussed in the context of a novel QD light-emitting diode. The spectral tunability of QDs combined with controlled nearest-neighbors and interparticle distances in their superlattice assemblies allow us to understand and potentially engineer excitonic energy flow in these unique material systems.<\/p>\n

  1. E. V. Shevchenko, D. V. Talapin, N. A. Kotov, S. O’Brien, and C. B. Murray, “Structural diversity in binary nanoparticle superlattices,” Nature<\/i>, vol. 439, pp. 55-59, Jan. 2006. [↩<\/a>]<\/li>
  2. S. A. Claridge, A. W. Castleman, S. N. Khanna, C. B. Murray, A. Sen, and P. S. Weiss, “Cluster-assembled materials,” ACS Nano<\/i>, vol. 3, pp. 244-255, Feb. 2009. [↩<\/a>]<\/li><\/ol>","protected":false},"excerpt":{"rendered":"

    Colloidal semiconductor nanocrystals or quantum dots (QDs) offer size-tunable absorption and luminescence spectra, permitting a broad range of applications in…<\/p>\n","protected":false},"author":370,"featured_media":1096,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[28,8,6083],"tags":[11492,12781,6131],"_links":{"self":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/posts\/1094"}],"collection":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/users\/370"}],"replies":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/comments?post=1094"}],"version-history":[{"count":10,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/posts\/1094\/revisions"}],"predecessor-version":[{"id":2298,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/posts\/1094\/revisions\/2298"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/media\/1096"}],"wp:attachment":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/media?parent=1094"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/categories?post=1094"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2013\/wp-json\/wp\/v2\/tags?post=1094"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}