Electroluminescence in plasma ion implanted silicon



Electroluminescent silicon is very desirable for its potential applications in computing and telecommunications. Plasma Ion Implantation (PII) is a means to modify the surface and sub-surface properties of silicon to produce luminescent centres. Silicon to be treated with PII is immersed in low-temperature plasma and biased to a high, negative voltage; this accelerates ions into the sample and implants them beneath its surface. The material is subsequently annealed in a furnace and fitted with thin gold and aluminium contacts. Samples of crystalline silicon were implanted with H ions, C ions, and N ions and found to emit visible light when subjected to electric current. Nearly every sample emitted light at ∼460 nm and ∼630 nm; these luminescence bands are commonly observed in X-ray excited optical luminescence studies of silicon nanostructures and have been attributed to silicon dioxide (SiO2) and the silicon-SiO2 interface, respectively [1]. Other luminescent bands may be the product of nanostructures and defects created by the implantation process and subsequent annealing. This presentation will explore in detail the results of these experiments and the potential of PII for modifying the luminescent properties of elemental silicon. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)