SiGe Impurity Electroluminescence

Silicon impurity lasers using P, As, Sb and Bi have been demonstrated to operate at low temperature with power outputs up to tens of mW and significant tunability at certain frequencies in the terahertz (for a review see Semicond. Sci. Technol. 20, S211 (2005)). While the performance is impressive compared to many other sources, an electrically pumped source would be preferable for most applications as this would remove the high power CO2 laser pump.

We were the first to demonstrate electroluminescence from impurities in boron doped modulation-doped SiGe quantum wells and later in a number of and Si/SiGe heterostructure systems (see above). In modulation-doped quantum wells, at the lowest temperatures only B-impurity lines are detected by FTIR spectroscopy but above 40 K, the intersubband transition between the LH1 and HH1 subbands is detected.

We are presently attempting to produce an electrically pumped impurity laser and have recently measured the lifetimes of the important impurity states using pump-probe techniques with a free electron laser as the pump (see above left).

Significant publications:

S.A. Lynch, S.S. Dhillon, R. Bates, D.J. Paul, D.D. Arnone, D.J. Robbins, Z. Ikonic, R.W. Kelsall, P. Harrison, D.J. Norris, A.G. Cullis, C.R. Pidgeon, P. Murzyn and A.Loudon, “Si-based electroluminescence at THz frequencies” Material Science and Engineering B 89, pp 10-12 (2002)

S.A. Lynch, P. Townsend, G. Matmon, D.J. Paul, Z. Ikonic, R.W. Kelsall, P. Harrison, D.J. Norris, A.G. Cullis, and D.D. Arnone, “Temperature dependence of terahertz optical transitions from boron and phosphorus dopant impurities in silicon” Applied Physics Letters 87, 101114 (2005)