Room-Temperature Near-Infrared Electroluminescence from Boron-Diffused Silicon Pn-Junction Diodes

Si Li,Deren Yang,Dongsheng Li,Ruixin Fan,Yuhan Gao

doi:10.3389/fmats.2015.00008

Abstract

Silicon pn junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski (CZ) n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL) was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 m (0.78 eV ) was observed besides the band-to-band line (~1.1eV) under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was observed. The intensity of peak at 0.78 eV increases exponentially with current injection with no observable saturation at room temperature. Furthermore, no dislocations were found in the cross-sectional transmission electron microscopy image, and no dislocation-related luminescence was observed in the low-temperature photoluminescence spectra. We deduce the 0.78 eV emission originates from the irradiative recombination in the strain region of diodes caused by the diffusion of large number of boron atoms into silicon crystal lattice.

Highlights

With the development of integrated circuits (ICs), the disadvantage of traditional metal interconnection structure, such as interlayer interference, energy dissipation, and signal delay, has become a bottleneck restricting the development of ultra-largescale integration circuits (USLIs)
It is necessary to notify that the SPR measures the activated dopant density only, which does not take into account the possible dopant clustering at the surface, so there can be a large amount of boron doping, which is inactive
Lots of lattice damage regions can be seen near the surface of Sample B in the transmission electron microscopy (TEM) image

Summary

Introduction

With the development of integrated circuits (ICs), the disadvantage of traditional metal interconnection structure, such as interlayer interference, energy dissipation, and signal delay, has become a bottleneck restricting the development of ultra-largescale integration circuits (USLIs). Many routes to fabricate efficient silicon light emitters have been proposed: porous silicon (Canham, 1990; Qin et al, 1996; Bisi et al, 2000; Zhao et al, 2005a,b), Si nanoprecipitates in SiO2 (Pavesi et al, 2000; Wang et al, 2007), erbium-doped Si (Ennen et al, 1983; Zheng et al, 1994; Polman et al, 1995), Si/SiO2 superlattice structures (Lu et al, 1995), and silicon pn-junction diodes (Sveinbjörnsson, 1996; Martin et al, 2001; Ng et al, 2001; Sun et al, 2004; Lourenco et al, 2005).

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