Strain compensated CdSe/ZnSe/ZnCdMgSe quantum wells as building blocks for near to mid-IR intersubband devices

• Published in: Journal of crystal growth 2015-09, Vol.425, p.207-211
• Main Authors: De Jesus, Joel, Chen, Guopeng, Hernandez-Mainet, Luis C., Shen, Aidong, Tamargo, Maria C.
• Format: Article
• Language: English
• Subjects: A3. Molecular beam epitaxy; A3. Quantum wells; B1. Cadmium compounds; B1. Zinc compounds; B2. Semiconducting II–VI materials; Cadmium selenides; Devices; Fourier transforms; Intermetallics; Quantum wells; Transmission electron microscopy; X-ray diffraction; Zinc selenides
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2014.12.021

In order to increase the conduction band offset of the ZnCdMgSe-based material system we studied the incorporation of strained CdSe layers to obtain deeper quantum wells for shorter wavelength intersubband transitions than those obtained in lattice-matched structures. Five CdSe/ZnSe/ZnCdMgSe multi-quantum wells (QW) samples grown by molecular beam epitaxy are studied in detail by transmission electron microscopy (TEM), X-ray diffraction (XRD), cw-photoluminescence (PL), and Fourier Transform Infrared (FTIR) absorption experiments. TEM and XRD results confirmed good structural quality of the samples. All the multi-QW PL energies were below the ZnCdSe lattice-matched to InP alloy bandgap (2.1eV), which serves as first evidence of having achieved deeper quantum wells. FTIR absorptions from 3.83 to 2.56μm were measured, shorter than those achieved by the lattice matched system. Simulations based on these results predict that absorptions as low as 2.18μm can be obtained with these materials. •Quantum wells (QW) of CdSe layers strained compensated with ZnSe are grown by MBE on InP substrates.•The multi-QW excellent quality is evidenced by XRD, TEM, and PL.•Deeper QW are confirmed by PL energies below the ZnCdSe lattice-matched to InP alloy bandgap (2.1 eV).•IR activity from 3.83 to 2.56 μm was measured, extending the range of the ZnCdMgSe-based alloys.•Simulations predict that absorptions as low as 2.18μm can be obtained with these materials.