Valence band offset in semimagnetic CdTe/(CdMn)To quantum wells

✍ Scribed by W. Ossau; B. Kuhn-Heinrich; A. Waag; T. Litz; G. Landwehr

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 263 KB
• Volume: 15
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1994.1097

✦ Synopsis

We present a comparative study of two different spectroscopic techniques in order to determine the valence band offset in (\mathrm{CdTe} /(\mathrm{CdMn}) \mathrm{Te}) quantum wells. On the one hand the energy difference between heavy- and light-hole excitons as a function of the heavy-hole transition energy is employed. We determine a valence band offset of (\mathrm{Q}_{\mathrm{v}}=0.30) for (\mathrm{CdTe} /(\mathrm{CdMn}) \mathrm{Te}), which is valid in the whole range of investigated (\mathrm{Mn}-) contents up to (x=0.27). An atternative determination of the valence band potential height is based on the tuning of potential heights due to external magnetic fields in semimagnetic quantum wells. Anslysing the Zeeman splitting of the heavy-hole exciton in (\mathrm{CdTe} /(\mathrm{CdMn}) \mathrm{Te}) quantum wells with different (\mathrm{Mn})-contents, we demonstrate a significant decrease of the valence band offset with increasing (\mathbf{M n})-content in the barrier. From the comparison of the two different spectroscopic methodes inchuding published data, we conchude that the valence band offset derived from the Zeemm splitting in CdTe/(CdMn)Te quantum wells with high Mn-content is strongly underestimated.