Future Trends in Microelectronics: Up the Nano Creek

Improvements in Light Emitters by Controlling Spontaneous Emission: From LEDs to Biochips

C. Weisbuch

Ecole Polytechnique, 91120 Palaiseau, France andMaterials Department, UC–Santa Barbara, Santa Barbara, CA 93106, U.S.A.

A. David

Materials Department, UC–Santa Barbara, Santa Barbara, CA 93106, U.S.A.

M. Rattier, L. Martinelli, H. Choumane, N. Ha, C. Nelep,A. Chardon, G.-O. Reymond, C. Goutel, and G. Cerovic

Genewave, bât. XTEC, Ecole Polytechnique, 91128 Palaiseau Cedex, France

H. Benisty

Labo. Charles Fabry de l’Institut d’Optique, CNRS, 91127 Palaiseau, France

1.   Introduction

The need to control electron and photon motion in solids, which would in particular enable better optoelectronic devices, has driven the field of light–matter interactions for the past thirty years.

Semiconductors, although uniquely useful for electrically pumped light emission, are hampered in this application by their high n ≥ 2.5 refractive index. At a planar face of a standard light-emitting diode (LED), extraction efficiency is limited to only η = 2−4% by the small fraction of internal emission that impinges at angles smaller than the critical angle, while substrate absorption usually consumes the remaining 96−98% of the internally reflected photons.^1,2 One possible solution to this drawback is to have light make multiple attempts to escape by impinging on the semiconductor-air interface at different angles. This is the solution offered by geometrical or ray optics, relying on shaped devices or ...