title: Metal-nitride-oxide-semiconductor light-emitting devices for general lighting.
abstract: The potential for application of silicon nitride-based light sources to general lighting is reported. The mechanism of current injection and transport in silicon nitride layers and silicon oxide tunnel layers is determined by electro-optical characterization of both bi- and tri-layers. It is shown that red luminescence is due to bipolar injection by direct tunneling, whereas Poole-Frenkel ionization is responsible for blue-green emission. The emission appears warm white to the eye, and the technology has potential for large-area lighting devices. A photometric study, including color rendering, color quality and luminous efficacy of radiation, measured under various AC excitation conditions, is given for a spectrum deemed promising for lighting. A correlated color temperature of 4800K was obtained using a 35% duty cycle of the AC excitation signal. Under these conditions, values for general color rendering index of 93 and luminous efficacy of radiation of 112 lm/W are demonstrated. This proof of concept demonstrates that mature silicon technology, which is extendable to low-cost, large-area lamps, can be used for general lighting purposes. Once the external quantum efficiency is improved to exceed 10%, this technique could be competitive with other energy-efficient solid-state lighting options.
authors.affiliation: MIND-IN2UB, Dept. Electrònica, Universitat de Barcelona, Martí i Fanquès 1, 08028, Barcelona, Spain. yberencen@el.ub.es
authors.forename: Y
authors.initials: Y
authors.lastname: Berencén
authors.forename: Josep
authors.initials: J
authors.lastname: Carreras
authors.forename: O
authors.initials: O
authors.lastname: Jambois
authors.forename: J M
authors.initials: JM
authors.lastname: Ramírez
authors.forename: J A
authors.initials: JA
authors.lastname: Rodríguez
authors.forename: C
authors.initials: C
authors.lastname: Domínguez
authors.forename: Charles E
authors.initials: CE
authors.lastname: Hunt
authors.forename: B
authors.initials: B
authors.lastname: Garrido