Abstract

Silicon is the most popular material for electronics industry. However, its applications in optics and optoelectronics are not as popular, mainly limited by the indirect-bandgap characteristics of silicon. Due to the mature fabrication processing technology, it is highly desired to make Si emit light. Although many methods had been invented to generate electroluminescence from Si [1], significant modification is usually required among them. In this work, we report a simple way of electroluminescence from Si. The structure is the same as the conventional metal-oxide-semiconductor (MOS) structure. The oxide is very thin so that carriers could tunnel through the oxide and make the device behave like a diode. Under forward bias, the MOS structure emit light at bandgap energy of Si. Increasing applied voltages, the emission at Si bandgap energy gradually vanishes and, meanwhile, shifts to wavelengths longer than 1200 nm. Fig. 1 shows a spectrum measure from MOS on n-type Si. The MOS structures made on both n-type and p-type Si have similar light-emitting behaviors. The simplicity of emitting light from both p-type and n-type silicon should make silicon an extremely powerful material for applications both in optics and electronics. The details of the emission and physics will be discussed in the presentation.

© 2000 IEEE