Crystalline Bi100−xSbx alloys are known as the first discovered topological insulators, well for their promising thermoelectric properties, while amorphous counterparts exhibit superconductivity (Tc > 6 K). However, strong tendency to crystallize has hindered both study and practical applications of Bi Bi–Sb alloys. To explore possibility obtaining superconducting phases enhancing we investigated ion-beam irradiation a method induce amorphization in We report experiments on pure using...

Schottky photodiodes based on Au-ZnMgO/sapphire are demonstrated covering the spectral region from 3.35 to 3.48 eV, with UV/VIS rejection ratios up ∼105 and responsivities as high 185 A/W. Both ratio responsivity shown be largely enhanced by presence of an internal gain mechanism, which compensated films become highly conductive a result illumination. This causes large increase in tunnel current through barrier, yielding gains that function incident photon flux.

Light polarization-sensitive UV photodetectors (PSPDs) using non-polar a-plane ZnMgO/ZnO multiple quantum wells grown both on sapphire and ZnO substrates have been demonstrated. For the PSPDs with anisotropic biaxial in-plain strain, responsivity absorption edge shifts by ΔE ∼ 21 meV between light polarized perpendicular (⊥) parallel (||) to c-axis, maximum (R) contrast is (R⊥/R||)max 6. ZnO, strain-free wells, 40 5. These polarization sensitivities explained in terms of excitonic...

A systematic analysis of the deep level spectrum in lower half bandgap Au–Zn1−xMgxO (0.056<x<0.18) Schottky diodes is presented. Two levels are observed at Ev+580 and Ev+280 meV regardless energy with trap concentrations linearly increasing Mg content. The concentration becomes as high 1.01×1018 cm−3 18% Mg, partially compensating films causing a decrease from 8.02×1016 to 1.27×1016 net electron an increase by three orders magnitude diode series resistance due trapping.

High quality 1 μm thick a-plane MgxZn1−xO layers were produced by molecular beam epitaxy with Mg contents higher than 50%. Resonant Rutherford backscattering spectrometry combined ion channeling revealed a uniform growth in both composition and atomic order. The lattice-site location of Mg, Zn O elements was determined independently, proving the substitutional behaviour Zn-sites wurtzite lattice. X-Ray diffraction pole figure analysis also confirms absence phase separation. Optical...

Deep level defects in n-type unintentionally doped a-plane MgxZn1−xO, grown by molecular beam epitaxy on r-plane sapphire were fully characterized using deep optical spectroscopy (DLOS) and related methods. Four compositions of MgxZn1−xO examined with x = 0.31, 0.44, 0.52, 0.56 together a control ZnO sample. DLOS measurements revealed the presence five levels each Mg-containing sample, having energy Ec − 1.4 eV, 2.1 2.6 V, Ev + 0.3 eV 0.6 eV. For all Mg compositions, activation energies...

Homoepitaxial ZnO/(Zn,Mg)O multiple quantum wells (MQWs) grown with m- and r-plane orientations are used to demonstrate Schottky photodiodes sensitive the polarization state of light. In both orientations, spectral photoresponse MQW shows a sharp excitonic absorption edge at 3.48 eV very low Urbach tail, allowing observation from A, B C transitions. The energy is shifted by ∼30 ∼15 meV for photodiodes, respectively, in full agreement calculated B, best figures merit obtained m-plane which...

The growth and performance of top-illuminated metamorphic In(0.20)Ga(0.80)As p-i-n photodetectors grown on GaAs substrates using a step-graded In(x)Ga(1-x)As buffer is reported. display low room-temperature reverse bias dark current density ~1.4×10(-7) A/cm(2) at -2 V. Responsivity specific detectivity values 0.72 A/W, 2.3×10(12) cm·Hz(1/2)/W 0.69 2.2×10(12) are achieved for Yb:YAG (1030 nm) Nd:YAG (1064 laser wavelengths V, respectively. A high theoretical bandwidth-responsivity product...

This work presents a comprehensive optical characterization of Zn 1 _ x Mg O thin films grown by spray pyrolysis (SP).Absorption measurements show the high potential this technique to tune bandgap from 3.30 4.11 eV changing acetate content in precursor solution, leading change Mg-content ranging 0 up 35%, as measured transmission electron microscopy-energy dispersive x-ray spectroscopy.The emission obtained cathodoluminescence and photoluminescence spectroscopy shows blue shift peak position...

The role that the mother substrate plays to influence performance of InGaN/GaN-based light-emitting diodes (LEDs) onto adhesive flexible tapes is addressed in this letter. For purpose, electroluminescent (EL) spectra and current density–voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$J$ </tex-math></inline-formula> – notation="LaTeX">$V$ ) characteristics flexi-LEDs are studied under different...

Detecting the UV part of spectrum is fundamental for a wide range applications where ZnMgO has potential to play central role. The shortest achievable wavelength function Mg content in films, which turn dependent on growth technique. Moreover, increasing contents lead an electrical compensation directly affects responsivity photodetectors. In addition, metal-semiconductor interface and presence grain boundaries have direct impact through different gain mechanisms. this work, we review...

Abstract The growth of Mg x Zn 1− O films both polar and nonpolar orientation in was successfully carried out by remote‐plasma‐enhanced MOCVD (RPE‐MOCVD) technique. face as‐grown film had a vertically aligned columnar with respect to the sapphire (11–20) substrate. These columns an average diameter about 40 nm. In contrast, sword‐shape lying width 250 nm on (10–12) Au/Schottky diodes (SDs) were fabricated c ‐plane (0001) O. A rectifying behavior been achieved series resistance increased...

We report on metal–semiconductor–metal (MSM) photodetectors (PDs) fabricated InAlGaN/GaN two-dimensional electron gas (2DEG) heterostructures. Electrical and photodetection properties were compared in two structures with without an AlN spacer between the barrier (InAlGaN) GaN. The presence of hugely reduces leakage current, allowing biasing at higher voltages. In photodetection, gain is obtained both a high bias. photocurrent transient behavior revealed faster response for excitation energy...

We review in this paper the application of ZnO/(Zn,Mg)O quantum wells to photodetection polarization state UV light. This is achieved by using natural anisotropy that exists non-polar wells, which separates excitonic absorption from three valence bands conduction band depending on incident light polarization. The device structures covered here consist Schottky photodiodes a- and m-plane orientations, grown molecular beam epitaxy ZnO or sapphire substrates, are analyzed as a function

By combining photoluminescence, capacitance-voltage profiling and deep level optical spectroscopy, the electrical signatures of levels induced by N in MBE-grown homoepitaxial m-ZnO layers are identified correlated to different physical origins. The films electrically compensated, with carrier concentrations that decrease from ~1 1016 cm−3 ~2 1015 as a result increasing incorporation. Regardless presence N, an intrinsic trap is found all at EV + 0.25 eV, most likely related VZn defects. More...