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Letter

Multicolor Light-Emitting Diodes Based on Semiconductor Nanocrystals Encapsulated in GaN Charge Injection Layers

Supporting Info

Alexander H. Mueller,^† Melissa A. Petruska,^† Marc Achermann,^† Donald J. Werder,^† Elshan A. Akhadov,^† Daniel D. Koleske,^‡ Mark A. Hoffbauer,*^† and Victor I. Klimov*^†

Los Alamos National Laboratory, Los Alamos, New Mexico 87545, and Sandia National Laboratories, Albuquerque, New Mexico 87185

Nano Lett., 2005, 5 (6), pp 1039–1044

DOI: 10.1021/nl050384x

Publication Date (Web): May 6, 2005

†

Los Alamos National Laboratory.

‡

Sandia National Laboratories.

Corresponding authors. E-mail: klimov@lanl.gov, mhoffbauer@lanl.gov.

Abstract

Numerous technologies including solid-state lighting, displays, and traffic signals can benefit from efficient, color-selectable light sources that are driven electrically. Semiconductor nanocrystals are attractive types of chromophores that combine size-controlled emission colors and high emission efficiencies with excellent photostability and chemical flexibility. Applications of nanocrystals in light-emitting technologies, however, have been significantly hindered by difficulties in achieving direct electrical injection of carriers. Here we report the first successful demonstration of electroluminescence from an all-inorganic, nanocrystal-based architecture in which semiconductor nanocrystals are incorporated into a p−n junction formed from GaN injection layers. The critical step in the fabrication of these nanocrystal/GaN hybrid structures is the use of a novel deposition technique, energetic neutral atom beam lithography/epitaxy, that allows for the encapsulation of nanocrystals within a GaN matrix without adversely affecting either the nanocrystal integrity or its luminescence properties. We demonstrate electroluminescence (injection efficiencies of at least 1%) in both single- and two-color regimes using structures comprising either a single monolayer or a bilayer of nanocrystals.

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