Silicon-based light emission after ion implantation

Electroluminescence of boron and phosphorus implanted samples has been studied for various implantation and annealing conditions. Phosphorus implantation is found to have a similar effect on light emission as boron implantation. The band-to-band luminescence of phosphorus implanted diodes is observed to increase by more than one order of magnitude upon rising the sample temperature from 80 K to 300 K and a maximum internal quantum efficiency of 2% has been reached at 300 K. The remarkably high band-to-band luminescence is attributed to a high bulk Shockley-Read-Hall lifetime, likely promoted by the gettering action of the implanted phosphorus. The anomalous temperature behavior of the efficiency can be explained by a temperature dependence of the lifetime characteristic of shallow traps. (c) 2004 Elsevier B.V. All rights reserved.