Luminescence and microstructure of Er/O co-doped Si structures grown by MBE using Er and SiO evaporation
2000 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, Vol. 3, no 5-6, 523-528 p.Article in journal (Refereed) Published
Er and O co-doped Si structures have been prepared using molecular-beam epitaxy (MBE) with fluxes of Er and O obtained from Er and silicon monoxide (SiO) evaporation in high-temperature cells. The incorporation of Er and O has been studied for concentrations of up to 2×1020 and 1×1021 cm-3, respectively. Surface segregation of Er can take place, but with O co-doping the segregation is suppressed and Er-doped layers without any indication of surface segregation can be prepared. Si1-xGex and Si1-yCy layers doped with Er/O during growth at different substrate temperatures show more defects than corresponding Si layers. Strong emission at 1.54µm associated with the intra-4f transition of Er3+ ions is observed in electroluminescence (EL) at room temperature in reverse-biased p-i-n-junctions. To optimize the EL intensity we have varied the Er/O ratio and the temperature during growth of the Er/O-doped layer. Using an Er-concentration of around 1×1020 cm-3 we find that Er/O ratios of 1:2 or 1:4 give higher intensity than 1:1 while the stability with respect to breakdown is reduced for the highest used O concentrations. For increasing growth temperatures in the range 400-575 °C there is an increase in the EL intensity. A positive effect of post-annealing on the photoluminescence intensity has also been observed.
Place, publisher, year, edition, pages
2000. Vol. 3, no 5-6, 523-528 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-47578DOI: 10.1016/S1369-8001(00)00075-5OAI: oai:DiVA.org:liu-47578DiVA: diva2:268474