The synthesis, crystal growth, and structural optoelectronic characterization has been carried out for the perovskite compound CsPbBr3. This is a direct band gap semiconductor which meets most of requirements successful detection X- γ-ray radiation, such as high attenuation, resistivity, significant photoconductivity response, with detector resolution comparable to that commercial, state-of-the-art materials. A phase transition occurs during growth at higher temperature does not seem affect...

The optical and electronic properties of Bridgman grown single crystals the wide-bandgap semiconducting defect halide perovskites A3M2I9 (A = Cs, Rb; M Bi, Sb) have been investigated. Intense Raman scattering was observed at room temperature for each compound, indicating high polarizability strong electron–phonon coupling. Both low-temperature room-temperature photoluminescence (PL) were measured compound. Cs3Sb2I9 Rb3Sb2I9 broad PL emission bands between 1.75 2.05 eV with peaks 1.96 1.92...

Gamma-ray detection and spectroscopy is the quantitative determination of their energy spectra, critical value critically important in diverse technological scientific fields. Here we report an improved melt growth method for cesium lead bromide a special detector design with asymmetrical metal electrode configuration that leads to high performance at room temperature. As-grown centimeter-sized crystals possess extremely low impurity levels (below 10 p.p.m. total 69 elements) detectors...

Solution-processed perovskites are promising for hard X-ray and gamma-ray detection, but there limited reports on their performance under extremely intense X-rays. Here, a solution-grown all-inorganic perovskite CsPbBr3 single-crystal semiconductor detector capable of operating at ultrahigh flux 1010 photons s-1 mm-2 is reported. High-quality single crystals fabricated into detectors with Schottky diode structure eutectic gallium indium/CsPbBr3 /Au. A high reverse-bias voltage 1000 V (435...

Thin layers of ZnO were grown on (0001) oriented sapphire by organometallic chemical vapor deposition. Low-temperature photoluminescence indicates that near-band-edge luminescence dominates the spectrum. In contrast to bulk material deep level for is relatively weak.

The blue and ultraviolet photoluminescence bands in Mg-doped GaN have been investigated over a wide range of temperatures excitation intensities. Redshifts the were observed with increasing temperature. underwent blueshift increased density. shifts 3.2 eV band are explained by potential fluctuation model for compensated semiconductor. In contrast, 2.8 essentially related to saturation luminescence from distant donor-acceptor pairs responsible this emission. Thermal quenching was at high an...

Semiconductor materials for efficient hard radiation detection are identified by combining a powerful chemical concept called dimensional reduction and precise theoretical electronic structure calculations. After more than 50 years of research development in the field, this constitutes significant step forward search new detector materials. Detailed facts importance to specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They...

Thin film ferroelectrics are being developed for integrated optics applications. Their major advantage lies in their large electro-optic coefficients. Furthermore, they nearly transparent from the mid-infrared to visible spectral region. With development of epitaxial deposition techniques ferroelectrics, waveguide structures with low optical loss have been demonstrated. Through use thin films deposited on low-index substrates, high-bandwidth modulators also attained.

Alternative all-inorganic halide perovskites are sought to replace the hybrid lead because of their increased stability. Here, (111)-oriented defect perovskite family A3M2X9 based on trivalent M3+ is expanded through use mixed halides, resulting in Cs3Bi2I6Cl3. This compound shares 2D bilayer structure α-Cs3Sb2I9 (space group P3̅m1), with Cl occupying bridging positions bilayers and I terminal sites, contrast parent Cs3Bi2I9, which consists 0D molecular [Bi2I9]3– dimers. The dimensionality...

Halide perovskites exhibit remarkably high-performance as semiconductors compared to conventional materials because of an unusually favorable combination optoelectronic properties. We demonstrate here that solution-grown single-crystals organic–inorganic hybrid perovskite CH3NH3PbI3 (MAPbI3), implemented in a Schottky-type device design, can produce outstanding hard radiation detectors with high spectral response and low dark current for the first time. MAPbI3 detector achieves excellent...

We have investigated the defect perovskites A3M2I9 (A = Cs, Rb; M Bi, Sb) as materials for radiation detection. The phase purity of Bridgman-grown single crystals was confirmed via high-resolution synchrotron X-ray diffraction, while density functional theory calculations (DFT) show surprisingly dispersive bands in out-of-plane direction these layered materials, with low effective masses both holes and electrons. Accordingly, each four showed response to 241Am α-particle irradiation hole...

The detection of γ-rays at room temperature with high-energy resolution using semiconductors is one the most challenging applications. presence even smallest amount defects sufficient to kill signal generated from which makes availability detectors a rarity. Lead halide perovskite exhibit unusually high defect tolerance leading outstanding and unique optoelectronic properties are poised strongly impact applications in photoelectric conversion/detection. Here we demonstrate for first time...

The optical and electrical properties of Mn-doped epitaxial GaN were studied. Low-temperature absorption measurements indicate the presence a Mn-related band with well-resolved fine structure. zero-phonon line is at 1.418±0.002 eV full width half maximum 20±1 meV. Two pseudolocal vibrational modes associated manganese observed energies hv1=20 hv2=73 Deep-level spectroscopy on lightly samples that Mn forms deep acceptor level Ev+1.42 eV. Using vacuum referred binding energy model for...

Epitaxial BaTiO3 thin films were grown in situ on (100) LaAlO3 by low-pressure organometallic chemical vapor deposition using the precursors Ba (hexafluoroacetylacetonate)2 (tetraglyme) and titanium tetraisopropoxide. The phase composition epitaxial quality sensitive to reactant partial pressures growth temperature. Deposition at 800 °C yielded [100]-oriented films. In-plane epitaxy was confirmed for x-ray diffraction.

We report that the chalcohalide compound Tl(6)SeI(4) is a promising material for efficient X-ray and γ-ray detection. This has higher figure of merit than current state-of-the-art room-temperature operation, Cd(0.9)Zn(0.1)Te (CZT). have synthesized high-quality single-crystalline wafers with detector-grade resistivities good carrier transport both electrons holes. demonstrate pulse height spectra recorded using Co-57 radiation show an energy resolution matching commercial CZT detector material.

The wide-band-gap semiconductor thallium gallium selenide (TlGaSe2) is promising for X-ray and γ-ray detection. In this study, the synthesis crystal growth of semiconducting TlGaSe2 was accomplished using a stoichiometric combination TlSe, Ga, Se modified Bridgman method. These large detector-grade crystals can be synthesized cut to dimensions appropriate detector. have mirror-like cleaved surfaces are transparent red, in agreement with band gap 1.95 eV observed absorption measurements....

Flame-melting rapid-cooling reactions were used to synthesize a number of pure phases the Cs2MIIMIV3Q8 family (MII = Mg, Zn, Cd, Hg; MIV Ge, Sn; Q S, Se, Te) whereas more toxic members synthesized using traditional tube furnace synthesis. All compounds presented here crystallize in noncentrosymmetric space group P212121, except for Cs2ZnGe3S8, which crystallizes centrosymmetric P21/n. The structures contain chains corner-sharing MIIQ4 and MIVQ4 tetrahedra linked by edge-sharing MIV2Q6 dimers...

The dielectric response of epitaxial BaTiO3 thin films deposited on MgO was measured through surface electrodes as a function applied bias, frequency, and temperature. room temperature value the constant ∼500 with dissipation factor, tan(δ), 0.05 at 100 kHz. Measurements varying bias field showed hysteresis tunability 30% for maximum ∼7 MV/m. frequency is well described by Curie–von Schweidler power law an exponent ∼0.04 in range 1 kHz–13 MHz. undergo diffuse phase transition temperatures...

Uniform films of the high Tc superconductor YBa2Cu3O7−δ have been prepared by organometallic chemical vapor deposition using volatile metalorganic precursors Cu(acetylacetonate)2, Y(dipivaloylmethanate)3, and Ba(heptafluorodimethyloctanedionate)2. With argon as a carrier gas water reactant, film growth rates 10–30 nm/min are achieved. After annealing under oxygen, energy dispersive x-ray analysis, profilometry, diffraction data reveal that such on [100] single-crystal MgO good compositional...

Second-harmonic generation of 1.064 μm incident light was measured on BaTiO3 thin films prepared by metalorganic chemical vapor deposition. Upon corona poling the film, second-harmonic signal significantly enhanced. The second-order nonlinear optical susceptibility, d, poled film reaches ∼7.5 times that quartz. enhanced shows a very slow decay at room temperature.