Zn x Cd 1– x Se/Zn x ′ Cd y ′ Mg 1– x ′– y ′ Se multi‐quantum well structures for intersubband devices grown by MBE

Applied Physics Letters

Tamargo

et al. 2006

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The authors report the observation of intersubband absorption in ZnxCd(1−x)Se∕Znx′Cdy′Mg(1−x′−y′)Se multiple quantum wells. Lattice-matched samples were grown by molecular beam epitaxy on InP (001) substrates. Photoluminescence measurements indicate that the samples have excellent material quality. The peak absorption wavelengths measured by Fourier transform infrared spectroscopy are 3.99 and 5.35μm for two samples with ZnxCd(1−x)Se well widths of 28 and 42Å, respectively. These values fall within the 3–5μm wavelength range, which is of interest for midinfrared intersubband devices, such as quantum cascade lasers and quantum well infrared photodetectors. Their experimental results fit well with theoretical predictions based on the envelope function approximation. The results indicate that these wide band gap II-VI materials are very promising for midinfrared intersubband device applications.

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confidence: 99%

Midinfrared intersubband absorption in ZnxCd1−xSe∕Znx′Cdy′Mg1−x′−y′Se multiple quantum well structures

Applied Physics Letters

Tamargo

et al. 2006

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Optical characterization of intersubband transitions in ZnxCd1−xSe∕Znx′Cdy′Mg1−x′−y′Se multiple quantum well structures by contactless electroreflectance

Applied Physics Letters

Charles

et al. 2006

Contactless electroreflectance was measured at room temperature to characterize a wide range of the possible optical transitions in ZnxCd1−xSe∕Znx′Cdy′Mg1−x′−y′Se multi-quantum-well structures grown by molecular beam epitaxy. Based on these measurements, the authors predict and then verify the anticipated intersubband transition energies. They investigate a representative Zn0.5Cd0.5Se∕Zn0.20Cd0.19Mg0.61Se structure, for which the E1-E2 transition energy is predicted to be 178meV (6.97μm). Intersubband absorption using Fourier transform infrared spectroscopy exhibits a peak at 180meV (6.89μm), in excellent agreement with the contactless electroreflectance measurements.

Study of intersubband transitions of ZnxCd1−xSe∕Znx′Cdy′Mg1−x′−y′Se multiple quantum wells grown by molecular beam epitaxy for midinfrared device applications

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

Tamargo

et al. 2007

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Two ZnxCd1−xSe∕Znx′Cdy′Mg1−x′−y′Se multiple quantum well structures were grown by molecular beam epitaxy. The quantum well layer thickness of the multiple quantum well region was varied in order to tune the intersubband transition energy. The high crystalline quality of the material was demonstrated by high resolution x-ray diffraction. Contactless electroreflectance (CER) spectroscopy and Fourier transform infrared (FTIR) spectroscopy were used to characterize the intersubband transitions. Excellent agreement between the estimated value obtained by CER and the value measured by FTIR was achieved. Intersubband absorption at 6.89 and 5.37μm was observed demonstrating the ability to tune the properties of these wide band gap II-VI materials for mid-IR intersubband device applications.