Si/SiGe quantum-cascade emitters for terahertz applications

✍ Scribed by D.J Paul; S.A Lynch; R Bates; Z Ikonić; R.W Kelsall; P Harrison; D.J Norris; S.L Liew; A.G Cullis; D.D Arnone; C.R Pidgeon; P Murzyn; J.-P.R Wells; I.V Bradley

• Book ID: 104428205
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 555 KB
• Volume: 16
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(02)00590-8

✦ Synopsis

The quantum cascade laser provides one possible method of realizing high e ciency light emission from indirect band gap materials such as silicon. Strain-symmetrized Si/SiGe samples designed to investigate the intersubband properties of quantum wells are examined. Electroluminescence data from Si/SiGe quantum-cascade staircases demonstrating edge emission from heavy-hole to heavy-hole transitions and light-hole to heavy-hole transitions are presented. In surface-normal emission only light-hole to heavy-hole electroluminescence is observed at 2:9 THz (103 m wavelength) as predicted by theory. Modulation-doped SiGe quantum well samples are also investigated to determine the underlying physics in the system. Results of picosecond time resolved studies of the dynamics of the intersubband transitions using a free electron laser are presented which show approximately constant relaxation times of 10 ps below 100 K.