Low temperature thermoreflectance of AlxGa1-xAs/GaAs quantum wells

✍ Scribed by V. Bellani; G. Guizzetti; L. Nosenzo; E. Reguzzoni; A. Bosacchi; S. Franchi

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 258 KB
• Volume: 13
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1993.1027

✦ Synopsis

Reflectance ( (R) ) and thermoreflectance (TR) of quantum well structures grown by MBE have been investigated at low temperature ( (30 \mathrm{~K}) ) in order to demonstrate the capabilities of (T R) to study quantum confined systems. Our results show that low temperature (T R) is a simple and yet very efficient technique which provides large signals ( (\Delta R / R>10^{3}) ), also in the case of reduced-dimensionality systems. We also show that (T R) can extract spectroscopic information from relatively high background reflectance and that it can be used to study transitions between subbands higher than the fundamental ones. The (T R) modulation mechanisms are discussed and the (T R) and (R) lineshapes are compared. The firstderivative nature of (T R) allows for a straightforward and reliable comparison between experiment and theory; this feature may have interesting applications in the study of QWs and SLs, where interference effects from the multilayer structure may complicate the analysis of the spectra.