A comparison of the photoluminescence decay of erbium in silicon and silicon-germanium

Photoluminescence decay times have been measured from n- and p-type silicon , a Si/Si1-xGex (x = 13%) multi quantum well structure, all implanted with Er, and a Si/Si1-xGex (x = 25%) MQW structure uniformly doped with Er durin g MBE growth. The decaying PL signal is recorded using a signal-averaging t ransient capture card. and decays over nearly three decades are acquired wi th a system response time of 10 mus. The Er luminescence is much more inten se in the Si/SiGe MQW structures than in silicon hosts. The method of Er-do ping in the Si/SiGe heterostructures does not alter the PL decay significan tly, but only one component is observed in the decay transient from the Er doped SiGe structures, compared with two in the PL decay of Er doped Si. (C ) 2001 Elsevier Science B.V. All rights reserved.