Ultra-high vacuum formation of silver films for light-emitting tunnel junctions

Integrated photonics requires compact electrically driven sources of optical radia-tion for the use in high-performance integrated circuits with optical interconnections in a chip. Light-emitting tunnel junctions represent a promising option of such nanosized light sources, even if their present quantum efficiency is insufficient for practical implementation. We pro-pose a technique for fabrication of such junctions by ultrahigh vacuum forming of thin silver films. Testing showed a high quality and high optical response of the produced films. Such films can serve as substrates for more complicated tunnel junction structures with yet higher quantum efficiency.