Study on temperature effect on properties of ZnO/MgZnO based quantum cascade detector in mid-infrared region

Abstract

The effect of temperature on a ZnO/Mg0.3Zn0.7O quantum cascade detector (QCD) in the mid-infrared region is investigated with consideration of bound-to-bound electronic-transport processes in the dark and under illumination. The temperature-dependent band structures of the QCD system, which comprises four quantum wells and five barriers in one period, are numerically calculated. The electronic transition is obtained with a standard electron-optical phonon Hamiltonian, and the photon absorption is described by the two-dimensional absorption coefficient. The responsivity of the ZnO/Mg0.3Zn0.7O QCD shows a good temperature stability without an obvious redshift, and the peak responsivity decreases by only 14% when the temperature increases from 50 to 300 K.

Velocity-field characteristics of MgxZn1−xO/ZnO heterostructures

“…𝑘 𝐵 is the Boltzmann constant, T is the absolute temperature, 𝐸 𝑓 is the Fermi level. The temperature-dependent bandgap of ZnO is calculated from [22],…”

Combinatorial Material Science and Strain Engineering Enabled by Pulsed Laser Deposition Using Radially Segmented Targets

“…Mg x Zn 1– x O is a well-investigated crystalline system which can be grown phase pure in the wurtzite structure up to alloy compositions of x ≈ 0.5 . The deposition under various conditions and methods including optical, electrical and structural characterizations has been intensively described in literature, − especially also for PLD. ,− It further has a wide range of applications in electronic or optoelectronic devices. ,− Because of the well-known variation of the bandgap and emission energy the Mg-content in thin films can be directly deduced from these properties. ,, Interface charges and an internal electric field due to high spontaneous and piezoelectric polarizations can lead to effects such as electron accumulation at interfaces (2DEG) or the quantum-confined Stark effect in MgZnO/ZnO quantum wells. − Graded Mg x Zn 1– x O structures so far have been rare in literature apart from graded quantum well structures and graded buffer layers already mentioned above.…”

The noise characteristics of MgZnO/ZnO quantum cascade detectors

“…16) QCDs fabricated from MgZnO/ZnO heterostructures can benefit from the tunable conduction band offset, and the detection range can be extended to include infrared radiation. 17,18) Another advantage is the high energy of LO-phonons in ZnO (72 meV), which can provide room for high detectivity. Thus, MgZnO/ ZnO is a promising material for preparing QCDs.…”

“…Thus, MgZnO/ ZnO is a promising material for preparing QCDs. 7,18,19) Jollivet et al reported ZnO/ZnMgO QCDs grown by molecular beam epitaxy. Their results showed that the TMpolarized intersubband absorption is peaked at 3 μm wavelength.…”

“…7) Recently, He et al investigated the influence of temperature on a ZnO/Mg 0.3 Zn 0.7 O QCD with numerical calculation and found that the peak responsivity decreases by only 14% from 50 K to 300 K with good temperature stability. 18) However, the noise characteristics of MgZnO/ ZnO QCDs are not mentioned in the above works. As is known, noise characteristics have a significant effect on the device performance of QCDs, such as the detectivity and responsivity.…”