Population inversion and intersubband electroluminescence in GaAs/AlGaAs triple barrier tunnelling structures

✍ Scribed by Y.B Li; J.W Cockburn; J.P Duck; M.S Skolnick; M.J Birkett; I.A Larkin; M Hopkinson; R Grey; G Hill

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 104 KB
• Volume: 2
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(98)00097-6

✦ Synopsis

We report the results of interband photoluminescence experiments on a series of GaAs/AlGaAs triple barrier tunnelling structures containing asymmetric coupled quantum wells. These experiments allow the relative populations of the n"1 (E1) and n"2 (E2) electron subbands of the wider quantum well (QW1) to be deduced when the structure is biased for tunnelling into the E2 level of QW1. The results show that a population inversion is obtained between E2 and E1 when the structure is designed so that the ground states of QW1 and the narrower quantum well (QW2) are energetically aligned at the E2 resonance bias. We have also observed mid-infra-red electroluminescence at "8.3 m from such a structure, arising from E2-E1 intersubband transitions within QW1.