Photoreflectance and Phototransmittance of Narrow Well Strained Layer In[sub]x[/sub]Ga[sub]1-x[/sub]As/GaAs Coupled Multiple Quantum Well Structures

S. H. Pan; H. Shen; Z. Hang; F. H. Pollak; Weihua Zhuang; Qian Xu; A. P. Roth; R. A. Masut; C. Lacelle; D. Morris

doi:10.1117/12.947309

18 August 1988 Photoreflectance and Phototransmittance of Narrow Well Strained Layer In_xGa_1-xAs/GaAs Coupled Multiple Quantum Well Structures

S. H. Pan, H. Shen, Z. Hang, F. H. Pollak, Weihua Zhuang, Qian Xu, A. P. Roth, R. A. Masut, C. Lacelle, D. Morris

Author Affiliations +

Proceedings Volume 0943, Quantum Well and Superlattice Physics II; (1988) https://doi.org/10.1117/12.947309
Event: Advances in Semiconductors and Superconductors: Physics and Device Applications, 1988, Newport Beach, CA, United States

Abstract

We have measured the photoreflectance (PR) spectra at 300K and 77K of two strained layer <001> InxGall-xAs/GaAs (x≈0.12) multiple quantum wells (MQW) with nominal well (Lz) and barrier (LB) widths of 50A/100A and 30A/100A, respectively, as deduced from the growth conditions. Phototransmittance at 77K of the latter sample has been studied. In both samples we have observed a number of features in the PR spectra corresponding to miniband dispersion (coupling between wells) of both confined and unconfined (above the GaAs barrier) transitions. The coupling between wells leads to different transition energies at the mini-Brillouin zone center (Γ) and edge (π) along the growth direction. This is the first observation of unconfined features and miniband dispersion in this system. Even though our samples have fairly wide barriers (LB ≈100A) the coupling between wells is an important effect because of the relatively small confinement energies for x≈0.12. Using the envelope function approach we have calculated the various transition energies taking into account both strain and quantum well effects, including miniband disper-sion. Good agreement with experiment is found for a heavy-hole valence band discontinuity of 0.3±0.05 and LZ/LB = 52±3A/105±5A(x=0.11±0.01) and 32±3A/95±5A(x=0.12±0.01) for the two samples, respectively. The In composition and well/barrier widths are thus in good agreement with the growth conditions. Although the symmetric component of the fundamental light-hole to conduction band transition is a strong feature, the small observed amplitude of the antisymmetric component for both samples is evidence for the type II nature of the light-hole to conduction band transitions.

Citation Download Citation

S. H. Pan, H. Shen, Z. Hang, F. H. Pollak, Weihua Zhuang, Qian Xu, A. P. Roth, R. A. Masut, C. Lacelle, and D. Morris "Photoreflectance and Phototransmittance of Narrow Well Strained Layer In_xGa_1-xAs/GaAs Coupled Multiple Quantum Well Structures", Proc. SPIE 0943, Quantum Well and Superlattice Physics II, (18 August 1988); https://doi.org/10.1117/12.947309

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available