Light-emitting silicon pn diodes

Abstract

We report on the electrical and optical characteristics of silicon light-emitting pn diodes. The diodes are prepared by ion implantation of boron at high doses and subsequent hightemperature annealing. Under forward bias, the diodes emit infrared electroluminescence closely below the band gap of bulk Si. We present a rate-equation model for bound excitons, free excitons and free carriers which successfully describes the electrical and optical behaviour of the diodes at low temperatures. Especially, an electrical bistability observed below 50 K is shown to be based on the interplay of bound excitons, free excitons and free carriers in the active area of the diodes. The ionisation of bound excitons is the origin of an improved electroluminescence from the diodes at higher lattice temperatures.PACS 78.60.Fi; 78.55.Ap; 71.55.Cn

Silicon‐based light emitting diode material studied under high pressure

“…The temperature results agree well with other authors EL [4,5] measurements and previously reported EL and PL [3].…”

“…Implantation damage is reduced by subsequent annealing. This method has been shown to produce efficient devices compatible with standard ultra large scale integration (ULSI) processing technology [3][4][5] with increased electroluminescence (EL) efficiency at room temperature. The proposed model for the increased EL efficiency of this material at room temperature is the introduction of dislocation loops which improves carrier confinement [3,6], excitonic traps which store and supply electron -hole pairs at elevated temperatures have also been suggested [7].…”

“…Silicon, however, is an indirect band-gap semiconductor making it fundamentally a poor emitter of light. Various routes have been tried to realise silicon-based emitters (see references contained in [3,4]). The diode material measured here is produced by implanting boron into an n-type substrate to form a p-n junction.…”

Excitation and pressure effects on photoluminescence from dislocation engineered silicon material

“…2. These temperature results agree well with previously reported electroluminescence (EL) and PL [3] and other authors EL [1,3] measurements on similar material. However, such results are anomalous and in contrast to the PL results for normal silicon substrates or other III-V compound materials, which show the apparent decrease in PL intensity with increasing temperature.…”

“…Ion implantation of boron into an n-type substrate to form p-n junction and recrystalization by annealing fabricate the diode material studied here. This method has been shown to produce efficient devices compatible with standard ultra large scale integration (ULSI) processing technology [1][2][3] with increased electroluminescence (EL) efficiency at room temperature. The proposed model for the increased EL efficiency of this material at room temperature is the introduction of dislocation loops which improves carrier confinement [3,4], although excitonic traps which store and supply electronhole pairs at elevated temperatures [5] and high bulk Shockley-Read-Hall lifetimes [6] have also been suggested.…”