ABSTRACT
In 1990, Canham (1990) discovered room-temperature strong visible photoluminescence (PL) from porous silicon (PS) fabricated electrochemically. This ,work was believed to be "opening the door of silicon-optoelectronic integration". However, further investigations indicated that PS has many disadvantages in application. Therefore, improving its stability becomes a subject of numerous investigations. At the end of 1996, Hirschman et al. (1996) showed that if PS is oxidized in diluted oxygen at temperature of 700-900 OC, its thermal and chemical stability can be greatly enhanced while retaining desirable lightemission and charge transport properties. However, the emission mechanism of this kind of partially oxidized PS (POPS) material is unclear and the emission efficiency needs to be further improved. In this work, we deposited Si or Ge thin layer on this kind of POPS material. Some new significant results were obtained. We will discuss all the results.
