{"id":2109,"date":"2010-07-14T15:36:07","date_gmt":"2010-07-14T19:36:07","guid":{"rendered":"https:\/\/wpmu2.mit.local\/?p=2109"},"modified":"2010-07-14T15:36:07","modified_gmt":"2010-07-14T19:36:07","slug":"experimental-and-theoretical-investigation-of-resonant-cavity-enhanced-colloidal-quantum-dot-light-emitting-diodes","status":"publish","type":"post","link":"https:\/\/wpmu2.mit.local\/experimental-and-theoretical-investigation-of-resonant-cavity-enhanced-colloidal-quantum-dot-light-emitting-diodes\/","title":{"rendered":"Experimental and Theoretical Investigation of Resonant-Cavity Enhanced Colloidal Quantum-dot Light-emitting Diodes"},"content":{"rendered":"
\"Figure<\/a>

Figure 1: Schematic of RC QD-LED.<\/p><\/div>\n

Quantum-dot light-emitting diodes (QD-LEDs), which capitalize on the excellent color saturation and high photoluminescence efficiencies offered by quantum dots (QDs), promise to be part of future generations of display technologies [1<\/a>]<\/sup>.\u00a0 The goal of our project is to integrate the QD-LED into a resonant cavity (RC) and enhance the intensity and the directionality of the QD electroluminescence (EL) akin to Schubert\u2019s study of RC GaAs LEDs [2<\/a>]<\/sup>.\u00a0 This enhanced QD emission may be of use in fields as diverse as optical communications, spectroscopy, and environmental and industrial sensing.<\/p>\n

\"Figure<\/a>

Figure 2: Comparison of EL spectra, images, and angular emission profiles of RC QD-LED and QD-LED. The RC QD-LED exhibits marked narrowing.<\/p><\/div>\n

The RC structure we are currently investigating (Figure 1) consists of a standard QD-LED [1<\/a>]<\/sup> grown on top of a distributed Bragg reflector (DBR).\u00a0 A DBR is a highly reflective mirror made of alternating layers of material with high and low indices of refraction.\u00a0 The Ag electrode on the top of QD-LED constitutes the other cavity mirror of the resonant cavity.\u00a0 With this structure, we have achieved narrowed emission, which is evident when comparing EL spectra and images of the QD-LED and the RC QD-LED (Figure 2).<\/p>\n

To better understand and optimize the device, we are currently modeling the device architecture to simulate the effect of the resonant cavity on the emission of the QD-LED.\u00a0 Our approach builds from first principles, calculating the optical modes of the system to deduce the coupling strength between the vacuum electric field and the QD transition dipole and then applying Fermi\u2019s golden rule to determine the spontaneous emission rate of the QDs.<\/p>\n

\r\nReferences
  1. S. Coe, W. K. Woo, M. Bawendi, and V. Bulovi\u0107, \u201cElectroluminescence from single monolayers of nanocrystals in molecular organic devices,\u201d Nature<\/em>, vol. 420, no. 6917, pp. 800-803, Dec. 2002. [↩<\/a>] [↩<\/a>]<\/li>
  2. E. F. Schubert, N. E. J. Hunt, M. Micovic, R. J. Malik, D. L. Sivco, A. Y. Cho, and G. J. Zydzik, Highly efficient light-emitting diodes with microcavities,\u201d Science<\/em>, vol 265, no. 5174, pp. 943-945, Aug. 1994. [↩<\/a>]<\/li><\/ol><\/div>","protected":false},"excerpt":{"rendered":"

    Quantum-dot light-emitting diodes (QD-LEDs), which capitalize on the excellent color saturation and high photoluminescence efficiencies offered by quantum dots (QDs),…<\/p>\n<\/div>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[12],"tags":[46,4228],"_links":{"self":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/2109"}],"collection":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/comments?post=2109"}],"version-history":[{"count":3,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/2109\/revisions"}],"predecessor-version":[{"id":2114,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/2109\/revisions\/2114"}],"wp:attachment":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/media?parent=2109"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/categories?post=2109"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/tags?post=2109"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}