Negatively charged excitons and the optical properties of modulation-doped quantum wells

✍ Scribed by K. Kheng; R.T. Cox; V.P. Kochereshko; K. Saminadayar; S. Tatarenko; Franck Bassani; A. Franciosi

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 348 KB
• Volume: 15
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1994.1050

✦ Synopsis

Optical and magneto-optical properties are studied for II-VI semiconductor multiple quantum wells (MQWs) doped with donors in the barriers to give electron concentrations of (210^{10}) to (610^{11} \mathrm{~cm}^{-2}) in the well layers. Following on from the recent identification of negatively charged excitons (\mathrm{X}^{-})(two electrons bound to one hole) in CdTe/Cd1-x (\mathrm{Zn}_{\mathrm{x}} \mathrm{Te}) MQWs, this paper presents more specifically the circular polarisation of the luminescence associated with (\mathrm{X}^{-})and with the normal exciton (\mathrm{X}) (one electron and one hole) in this type of structure. Very similar magnetooptical properties are observed for modulation doped (\mathrm{Zn} 0.9 \mathrm{Cd} 0.1 \mathrm{Se} / \mathrm{ZnSe}) (\mathrm{MQWs}), and (\mathrm{X}^{-})is identified in these wells with a binding energy as large as (7 \mathrm{meV}) for the second electron at (50 \AA) well-width.