Electrically tunable white-color electroluminescence from Si-implanted silicon nitride thin film

Abstract

Visible electroluminescence (EL) with two composite bands, i.e., a violet band and a green-yellow band has been observed from Si-implanted silicon nitride thin films. By varying the intensity ratio of the two composite EL bands in terms of the injection current, strong white-color EL can be achieved at certain injection currents (e.g., ~265 mA/cm(2)). The observed transition in EL color from violet to white under different injection conditions is studied based on the understanding that the violet band is originated from silicon nitride matrix while the green-yellow band is related to the implanted Si. The Si-implanted silicon nitride thin film offers the possibility of electrically tunable white-light Si-based light emitters.

Metal-nitride-oxide-semiconductor light-emitting devices for general lighting

“…3(d) shows a photograph of the MNOSLED device (A1) with the emitted orange-white light. A bi-layer or tri-layer structure like those reported here are expected to have red-infrared luminescence from Si-nc in the oxide and/or nitride and blue-green luminescence of Si based defects in the silicon nitride [19,25,26]. Note that when silicon precipitates have been observed (by electron microscopy) in a silicon nitride matrix, red emission is reported as well [23].…”

“…Consequently, the peak around 535 nm is attributed to the luminescence of the SRSN. In particular, it has been reported that luminescent centers associated to defects, such as Si-dangling bonds located in the middle of the band-gap, as well as bonding states of Si-Si units that are close to the valence band edge, emit at this wavelength [25,26]. In similar layers, luminescence lifetimes in the ns and µs range are ascribed to silicon nitride defects and Si-nc into silicon oxide matrix, respectively, according to dynamic studies reported [19,27].…”

Blue–green to near-IR switching electroluminescence from Si-rich silicon oxide/nitride bilayer structures

“…Charge transport analysis is reported and allows for identifying the origin of this twowavelength switching effect. © 2011 Optical Society of America OCIS codes: 250.0250, 230.2090, 230.6080, 260.3800.Silicon-rich silicon oxide (SRSO) and silicon-rich silicon nitride (SRSN) have drawn great interest in the last decades as active dielectric matrices in optoelectronic devices [1][2][3][4]. Particularly, these materials have been used in the fabrication of low-cost light emitting devices compatible with the mainstream Si technology, They also provide a solution to the monolithic integration of electronic and optical technologies on the same Si chip.…”

Luminescent Devices Based on Silicon-Rich Dielectric Materials

“…Intrinsic emission has been also observed in SRN ilms [27][28][29][30][31]. For example, an orange emission at 600 nm was observed at room temperature and has been related to the electron-hole pairs' recombination within Si-nps [27].…”

“…Some other authors have shown signiicant improvement of the green emission intensity using oxidized silicon-rich nitride [29]. Also, when a silicon nitride ilm is implanted with Si ions, violet and green-yellow emission bands are observed, giving rise to an intense white EL emission [30]. The violet band was related with the presence of defects states related to silicon dangling bonds (=Si 0 or centers K 0 ) located near the middle of the forbidden gap of silicon nitride and defect states related to the unit Si-Si= located near the edge of the valence band, while the green-yellow band was atributed to the transition from the =Si 0 state to nitrogen dangling bonds (=N-) in the tails of valence bands.…”