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

Abstract

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.

Thermal annealing effects on intersubband transitions in (CdS∕ZnSe)∕BeTe quantum wells

“…The recent development of II-VI low-dimension structures has opened up the application of II-VI materials in the mid-or near-infrared ͑IR͒ spectral region. [5][6][7][8][9] The ͑CdS / ZnSe͒ / BeTe QWs reported in this letter have a type-II band alignment with a huge conduction band offset of 3.1 eV. 10 Most recently, we have observed the ISB-T down to ϳ1.5 m in this structure.…”

Optical characterization of intersubband transitions in ZnxCd1‐xSe/Znx′Cdy′Mg1‐x′‐y′Se asymmetric coupled quantum well structures by contactless electroreflectance

“…[5]. Following the previously reported values for the CBO, we have assumed that the CBO is 0.80 of the band gap difference between the barriers and wells [6]. The calculated transition energies are listed in Table 1.…”

Wide band gap II–VI selenides for short wavelength intersubband devices

“…We have proposed the use of wide band gap II-VI semiconductors as an alternative material system for short wavelength ISB devices [12]. In this paper, we summarize our results of ISB electroluminescence (EL) in ZnCdSe/ZnCdMgSe QC structures.…”