Light emitting diodes on Si

摘要

To extend the usage of silicon as light emitter in optoelectronics, two ways are exploited to overcome its indirect bandgap obstacle. Metal-oxide-semiconductor structures with silicon dioxide (SiO_2) nanoparticles as oxide layer exhibits electroluminescence with 1.5x10~(-4) external efficiency at Si bandgap energy. The enhancement in light emission is attributed to carrier concentration due to non-uniformity of oxide thickness. Another approach is to take advantage of direct bandgap materials. Chemically synthesized cadmium sulfide (CdS) nanoparticles are deposited on Si substrate and exhibits electroluminescence corresponding to different process treatment.