Transport and luminescence phenomena in electroformed silicon nitride-based light emitting diode

Abstract

Hydrogenated amorphous silicon nitride-based heterojunction pin diode was electroformed under sufficiently high forward bias stress leading to its instant nanocrystallization at room temperature. In order to investigate the origin of the accompanying bright visible light emission, current-voltage and electroluminescence (EL) characteristics of the electroformed diode were scanned over temperature. Electrical transport mechanism was analysed in the low, medium and high electric field regimes. Temperature and field dependence of thermal activation energy were discussed. EL characteristics were studied using the spectral energy distribution and the injection current dependence of its intensity. Thermal quenching data of EL and photoluminescence intensities were compared. Finally, the relationship between the electrical transport and luminescence phenomena was attempted to be interpreted within the frame of a self-consistent model.

Influence of sublayer thickness on electroluminescence from a-Si:H/SiNx superlattice structures

“…There are a lot of possible origins of the electroluminescence in a-Si: H/SiN x SLs. The EL may be caused by quantum confinement effect in the structure, or by luminescence from localized states in the a-Si:H and SiN x interface, or by localized states inside the bulk of SiN x sublayers [13]. Also the emission in near-IR band could be related to the light emission from Si nanoparticles embedded in the silicon nitride matrix [24].…”

“…Superlattice structures (SLs) of Si/SiN x [8,9], Si/SiO x N y [10], SiN x /SiN y [11] and Si/ SiO 2 [12] are investigated and SiN x based superlattice is showing promising results for LED application due to the lower barrier height for both hole and electron injection into the active region compared to SiO 2 structures. The light emission is interpreted by either interfacial defect assisted radiative recombination or quantum confinement effect, however, the mechanism of electroluminescence (EL) is still under debate [13]. The influence of size of Si nanocrystallites, annealing conditions and the role of barrier layers to EL are investigated [11,14,15].…”

SEM, EDX spectroscopy and real-time optical microscopy of electroformed silicon nitride-based light emitting memory device

“…1). For this purpose, 90 nm p + nanocrystalline Si (p + nc-Si:H), 30 nm intrinsic a-SiN x :H and 90 nm n + nc-Si:H films were grown consecutively by an Oxford Instruments PECVD system using the deposition recipe given before [9]. The surface images of the ITO top electrodes of both as-deposited and electroformed diodes were obtained by Carl Zeiss Ultra Plus Gemini FE-SEM.…”

“…Our group studied the Contribution to the Topical Issue "Disordered Semiconductors: Physics and Applications", edited by Jean-Paul Kleider, Erik Johnson, Rudolf Brüggemann. * e-mail: anutgan@gmail.com electroforming of both a-Si:H based homojunction [7] and hydrogenated amorhous silicon nitride (a-SiN x :H) based heterojunction [8,9] p-i-n diodes. As we also observed enhanced EL in both type of diodes, it seems that strong light emission is the common consequence of electroforming in p-i-n diodes.…”