Light emission from silicon: Some perspectives and applications

Abstract

Research on efficient light emission from silicon devices is moving toward leading-edge advances in components for nano-optoelectronics and related areas. A silicon laser is being eagerly sought and may be at hand soon. A key advantage is in the use of silicon-based materials and processing, thereby using high yield and low-cost fabrication techniques. Anticipated applications include an optical emitter for integrated optical circuits, logic, memory, and interconnects; electro-optic isolators; massively parallel optical interconnects and cross connects for integrated circuit chips; lightwave components; highpower discrete and array emitters; and optoelectronic nanocell arrays for detecting biological and chemical agents. The new technical approaches resolve a basic issue with native interband electro-optical emission from bulk Si, which competes with nonradiative phonon-and defect-mediated pathways for electron-hole recombination. Some of the new ways to enhance optical emission efficiency in Si diode devices rely on carrier confinement, including defect and strain engineering in the bulk material. Others use Si nanocrystallites, nanowires, and alloying with Ge and crystal strain methods to achieve the carrier confinement required to boost radiative recombination efficiency. Another approach draws on the considerable progress that has been made in high-efficiency, solar-cell design and uses the reciprocity between photo-and light-emitting diodes. Important advances are also being made with siliconoxide materials containing optically active rare-earth impurities.

Strong Efficiency Improvement of SOI-LEDs Through Carrier Confinement

“…2(a)]. A monotonous increase of EL is observed, while the quantum-size effect is known to be significant only when the silicon layer thickness is below 10 nm [13], [14]. The electroluminescence is inversely proportional to the access region thickness in the full range.…”

Photonics Application of Silicon Nanocrystals

“…One of the more appealing properties of Si-nc is the possibility to get light by current injection into the Si-nc and thus enabling LEDs [108][109][110][111]. The main difficulty in obtaining efficient LEDs is to get efficient carrier injection.…”

Highly Sensitive Porous Silicon Sensor: Detection of Organic Vapours Using Photoluminescence Quenching Technique

“…Physical and optical properties of porous silicon (PS) have attracted much attention in the past few years [1,2]. The advantages of PS over its crystalline form include large surface to volume ratio, quantum confinement effects, ease of tuning bandgap for efficient light emission, and high sensing capabilities.…”