Abstract
This paper attempts to review the field of research into light emission from porous silicon. The driving force behind such research is the tantalizing goal of adding optoelectronic functions to the already impressive array of electronic functions provided by silicon-based devices. A silicon technology with included light emission would move even closer to complete dominance of the electronics market. After several years of research effort, the fundamental mechanisms of light emission are still not completely resolved. This is not surprising: porous silicon has many attributes of a new and complex material, and its study requires a truly interdisciplinary effort involving electrochemistry, surface science, structural and chemical microscopy on the atomic scale and detailed optical spectroscopy. This paper tries to connect these various threads; inevitably what emerges will only serve as a rather selective 'snapshot' of a still developing and often perplexing field.