An electrical and optical study of electrons in triple barrier structures

✍ Scribed by C.-Y. Kuo; M.A. Lynch; A.H. Roberts; P.D. Buckle; P. Dawson; M. Missous; W.S. Truscott

• Book ID: 104429207
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 92 KB
• Volume: 2
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(98)00166-0

✦ Synopsis

Current-voltage curves measured over the temperature range 13-300 K show three shoulders and/or peaks common to most of a series of MBE-grown GaAs/Al V Ga \V As triple-barrier resonant tunnelling structures. The widths of the barriers (x"&0.33) were &49, &58 and &49 A > ; one well width was fixed between 72 and 68 A > and the other varied between 68 and 45 A > . Photoluminescence (PL) and PL excitation spectroscopy and a self-consistent Poisson-Schro¨dinger model suggest that the features are associated with (i) the maximum in the transparency of the barrier region when the two electron levels in the wells are aligned, (ii) a cut-off in phonon emission assisted tunnelling between the wells when the separation of these levels exceeds the optical phonon energy of 36 meV, and (iii) cut-off of coupling between electrons in the negative contact and the states in the adjacent well.