Enhanced spontaneous emission in a photonic crystal light-emitting diode
  We report direct evidence of enhanced spontaneous emission in a photonic crystal (PhC) light-emitting diode. The device consists of p-i-n heterojunction embedded in a suspended membrane, comprising a layer of self-assembled quantum dots. Current is injected laterally from the periphery to the center of the PhC. A well-isolated emission peak at 1300nm from the PhC cavity mode is observed, and the enhancement of the spontaneous emission rate is clearly evidenced by time-resolved electroluminescence measurements, showing that our diode switches off in a time shorter than the bulk radiative and nonradiative lifetimes 
M. Francardi, L. Balet, A. Gerardino, N. Chauvin, D. Bitauld, L.H. Li,   B. Alloing, and A. Fiore