ELECTROCHEMICAL DOPING OF POROUS SILICON WITH RARE-EARTH ELEMENT

Doping of rare earth element such as erbium into optical fibre to form light amplifier as been realised. It is also recognised that rare ear th can provide a strong luminescence center for many materials. Conven tional doping of rare earth elements in semiconductors is by ion impla ntation. Here we like to report that praseodymium has been successfull y implanted into porous silicon using electrochemical method. This met hod is simple and potentially can be scaled up to industrial productio n. XPS analysis confirmed the presence of praseodymium in porous silic on. Strong electroluminescence was observed from the doped porous sili con. By varying the current density we have observed emission of spect ra varied from red to green. The electroluminescence spectrum was simi lar to that of photoluminescence, except there was a distinct shoulder peak at the red-end of the electroluminescence spectrum.