Optical Investigation of the Band Offset of CdxZn1−xTe /ZnTe and ZnSexTe1−x/ZnTe Superlattices

1990 ◽  
Vol 198 ◽  
Author(s):  
Y. Rajakarunanayake ◽  
M. C. Phillips ◽  
J. O. Mccaldin ◽  
D. H. Chow ◽  
D. A. Collins ◽  
...  
Keyword(s):  
Valence Band ◽  
Band Alignment ◽  
Band Offset ◽  
Type I ◽  
Optical Investigation ◽  
Type Ii ◽  
Carrier Injection ◽  
Valence Band Offset ◽  
Small Component ◽  
Strained Layer Superlattices

ABSTRACTWe have analyzed photoluminescence spectra from CdxZnl−xTe /ZnTe and ZnSexTel−x/ZnTe strained layer superlattices grown by MBE, and obtained the band offsets by fitting to theory. We find that the valence band offset of the CdTe/ZnTe system is quite small (-50± 160 meV). In CdxZnl−xTe /ZnTe superlattices, the electrons and heavy holes are confined in the CdxZn1−xTe layers (type I), while the light holes are confined in the ZnTe layers (type II). On the other hand, the photoluminescence data from the ZnSexTe1−x /ZnTe superlattices suggest that the band alignment is type II, with a large valence band offset (−907 ± 120 meV). We also investigated the band bowing in the ZnSexTel−x alloys by optical spectroscopy, and found that there is only a small component of bowing in the valence band, while most of the bowing occurs in the conduction band. Based on our results for band alignments, we evaluate the prospects for minority carrier injection in wide bandgap heterostructures based on ZnSe, ZnTe, and CdTe.

Exciton binding energies and the valence-band offset in mixed type-I–type-II strained-layer superlattices

1992 ◽  
Vol 46 (3) ◽  
pp. 1557-1563 ◽  
Author(s):  
P. Peyla ◽  
Y. Merle d’Aubigné ◽  
A. Wasiela ◽  
R. Romestain ◽  
H. Mariette ◽  
...  
Keyword(s):  
Valence Band ◽  
Mixed Type ◽  
Binding Energies ◽  
Band Offset ◽  
Type I ◽  
Type Ii ◽  
Valence Band Offset ◽  
Strained Layer ◽  
Strained Layer Superlattices

Theory of Interfaces in Wide-Gap Nitrides

1996 ◽  
Vol 449 ◽  
Author(s):  
M. Buongiorno Nardelli ◽  
K. Rapcewicz ◽  
E. L. Briggs ◽  
C. Bungaro ◽  
J. Bernholc
Keyword(s):  
Laser Diodes ◽  
Blue Laser ◽  
Band Offset ◽  
Type I ◽  
Interface Properties ◽  
Type Ii ◽  
Valence Band Offset ◽  
Bulk Properties ◽  
Conduction Band Offset ◽  
Zinc Blende

ABSTRACTThe results of theoretical studies of the bulk and interface properties of nitrides are presented. As a test the bulk properties, including phonons of GaN at the Γ-point, are calculated and found to be in excellent agreement with the experimental data. At interfaces, the strain effects on the band offsets range from 20% to 40%, depending on the substrate. The AlN/GaN/InN interfaces are all of type I, while the Al0.5Ga0.5N on A1N zinc-blende (001) interface is of type II. Further, an interface similar to those used in the recent blue laser diodes is of type I and does not have any electronically active interface states. The valence band-offset in the (0001) GaN on A1N interface is -0.57 eV and the conduction band-offset is 1.87 eV.

Direct Optical Measurement of the valence band offset of p+ Si1−x−yGexCy/p− Si (100) by Heterojunction Internal Photoemission

1998 ◽  
Vol 533 ◽  
Author(s):  
C. L. Chang ◽  
L. P. Rokhinson ◽  
J. C. Sturm
Keyword(s):  
Valence Band ◽  
Optical Measurement ◽  
Chemical Vapor ◽  
Band Alignment ◽  
Band Offset ◽  
Valence Band Offset ◽  
Strained Si ◽  
Internal Photoemission ◽  
Capacitance Voltage ◽  
Absorption Measurements

AbstractOptical absorption measurements have been performed to study the effect of carbon on the valence band offset of compressively strained p+ Si1−x−yGexCy/(100) p− Si heterojunction internal photoemission structures grown by Rapid Thermal Chemical Vapor Deposition (RTCVD) with substitutional carbon levels up to 2.5%. Results indicated that carbon decreased the valence band offset by 26 ± 1 meV/ %C. Results from optical measurement in this study agreed with previous data from capacitance-voltage measurements. Based on previous reports of carbon effect on the bandgap of compressively strained Si1−x−yGexCy, our work suggests that the effect of carbon incorporation on the band alignment of Si1−x−yGexCy/Si is to reduce the valence band offset, with a negligible effect on the conduction band alignment.

scholarly journals Determination of valence-band offset at cubic CdSe/ZnTe type-II heterojunctions: A combined experimental and theoretical approach

2012 ◽  
Vol 86 (19) ◽  
Author(s):  
Daniel Mourad ◽  
Jan-Peter Richters ◽  
Lionel Gérard ◽  
Régis André ◽  
Joël Bleuse ◽  
...  
Keyword(s):  
Valence Band ◽  
Theoretical Approach ◽  
Band Offset ◽  
Type Ii ◽  
Valence Band Offset

scholarly journals Calculation of Band Offsets of Mg(OH)2-Based Heterostructures

2021 ◽  
Vol 2 (3) ◽  
pp. 274-283
Author(s):  
Masaya Ichimura
Keyword(s):  
Solar Cells ◽  
Valence Band ◽  
Dye Sensitized Solar Cells ◽  
Band Alignment ◽  
First Principles Calculation ◽  
Band Edge ◽  
Level Energy ◽  
Type I ◽  
Valence Band Edge ◽  
Generalized Gradient

The band alignment of Mg(OH)2-based heterostructures is investigated based on first-principles calculation. (111)-MgO/(0001)-Mg(OH)2 and (0001)-wurtzite ZnO/(0001)-Mg(OH)2 heterostructures are considered. The O 2s level energy is obtained for each O atom in the heterostructure supercell, and the band edge energies are evaluated following the procedure of the core-level spectroscopy. The calculation is based on the generalized gradient approximation with the on-site Coulomb interaction parameter U considered for Zn. For MgO/Mg(OH)2, the band alignment is of type II, and the valence band edge of MgO is higher by 1.6 eV than that of Mg(OH)2. For ZnO/Mg(OH)2, the band alignment is of type I, and the valence band edge of ZnO is higher by 0.5 eV than that of Mg(OH)2. Assuming the transitivity rule, it is expected that Mg(OH)2 can be used for certain types of heterostructure solar cells and dye-sensitized solar cells to improve the performance.

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