Band structure of very narrow InGaAs/InP quantum wells with gradual interface effects

✍ Scribed by F. Dujardin; N. Marréaud; J.P. Laurenti

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 115 KB
• Volume: 22
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0432

✦ Synopsis

Band structure calculations are performed on narrow InGaAs/InP quantum wells (QWs) including gradual interface effects. Within the confines of the envelope approximation, the transfer matrix method is used, with adaptation to multi-band models. A comparison is made for two structures with fundamental absorption edges near 1.3 µm, an abrupt eight monolayers (ML)-wide lattice-matched In 0.532 Ga 0.468 As/InP QW, as a reference, and a QW with a gradual profile because of interface effects. With respect to the reference QW, the inplane electron effective mass in the gradual structure is slightly higher. The distance between heavy hole (HH) and light hole (LH) subbands is enhanced. Due to an asymmetric profile, a splitting occurs for the hole subbands, equivalent to that induced by a 500 kV cm -1 electric field in the reference QW. The HH in-plane effective mass is not significantly affected by the interface effects. For LHs, the upper branch remains electron-like and the associated in-plane effective mass is slightly reduced (in absolute value), while the lower branch is hole-like with a large value of effective mass.