Patent ID: 8093604

Claim:
A light emitting structure comprising: a layer stack including: a first active layer including a concentration of luminescent centers, for emitting light at a first wavelength, requiring a first excitation energy characteristic of the first active layer; and a first buffer layer comprising a wide bandgap semiconductor or a dielectric material adjacent to the first active layer; and a set of electrodes for applying to the layer stack an electric field for excitation of light emission; wherein the first buffer layer has a first thickness, in the direction of the electric field, proportionally matched to on the first excitation energy, and wherein electrons gain energy from the electric field, when passing through the first buffer layer, proportional to the first thickness and matched to the first excitation energy, to excite the luminescent centers in the first active layer via impact ionization or impact excitation substantially at said first excitation energy for light emission at the first wavelength.