Boron engineered dislocation loops for efficient room temperature silicon light emitting diodes

Abstract

The dislocation engineered approach makes use of the controlled introduction of dislocation loops into silicon substrates by conventional ion implantation and thermal processing. The dislocation loops introduce a local strain field, which modifies the band structure and provides spatial confinement of the charge carriers, thus allowing strong intrinsic silicon band-edge luminescence to be observed at room temperature. Efficient silicon-based dislocation engineered light emitting diodes were fabricated under different process conditions to study the influence of the dislocation loops formation on the luminescence properties. Electroluminescence and transmission electron microscopy techniques were used to characterise the devices and the results showed that (i) the size and density of the loops vary with boron implant energy and post-implant anneal conditions and (ii) the luminescence response from such devices can be directly related to the size and density of the dislocation loops.