Silicon Avalanche Based Light Emitting Diodes and Their Potential Integration into CMOS and RF Integrated Circuit Technology

Abstract

As a rapid growing field in worldwide science and technology, silicon nano-photonics has become one of the most promising photonics integration platforms in the last decade. This is mainly due to the combination of a very high index contrast and the availability of silicon complementary metal-oxide-semiconductor (CMOS) fabrication technology, which allows the use of electronics fabrication facilities to make photonic circuitry. Unfortunately, the indirect band-gap of silicon leads to low efficiency and slow efficiency that is unexpected. The rate of electron-hole recombination in silicon material is too low to produce emitted photons in forward biased silicon p-n junctions, but light emission observed from reverse-biased silicon p-n junctions under high electric field was already reported in 1955 by Newman [1]. The radiative transition between hot carriers emits photons larger than the energy gap. Hence the luminescence during avalanche breakdown is characterized by a broad emission spectrum. An example of the high-energy edges of avalanche-breakdown luminescence is shown in Fig. 1. The low-energy edge of the emission spectrum, on the other hand, extends to energies lower than the gap energy, due to the tunneling-assisted photon emission [2].