CES 2015: What the Heck Are Quantum Dots? – IEEE Spectrum

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1. May 30, 2016 at 8:51 am

   Tomi Engdahl says:

   Quantum Dots Deep Into Hybrid LEDs
   http://www.eetimes.com/document.asp?doc_id=1329779&

   Boasting record-breaking color conversion effective quantum yields, an international team of researchers has designed a novel photonic quasi-crystal LED structure that deeply embeds quantum dots within the whole stack of the LED’s active layers.

   The researchers first grew a LED stack of GaN/InGaN Multi-Quantum Well (MQW) onto a sapphire substrate, and then used nano-imprint lithography and plasma etching to “punch” the whole stack and structure it as a 12-fold symmetric quasi-crystal (PQC).

   When used for LED colour conversion, colloidal quantum dots (QDs) are usually dispersed into an encapsulation layer above the active LED structure, missing out the majority of the light emitted by the LED (60% to 80% of which remaining trapped within the epitaxy layers due to total internal reflection).

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