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In this work, we demonstrate the performance of a silicon-compatible, high-performance, and self-powered photodetector. A wide detection range from visible (405 nm) to near-infrared (1550 nm) light was enabled by the vertical p-n heterojunction between the p-type antimony telluride (Sb 2 Te 3 ) thin film and the n-type silicon (Si) substrates. A Sb 2 Te 3 film with a good crystal quality, low density of extended defects, proper stoichiometry, p-type nature, and excellent uniformity across a 4 in. wafer was achieved by atomic layer deposition at 80 °C using (Et 3 Si) 2 Te and SbCl 3 as precursors. The processed photodetectors have a low dark current (∼20 pA), a high responsivity of (∼4.3 A/W at 405 nm and ∼150 mA/W at 1550 nm), a peak detectivity of ∼1.65 × 10 14 Jones, and a quick rise time of ∼98 μs under zero bias voltage. Density functional theory calculations reveal a narrow, near-direct, type-II band gap at the heterointerface that supports a strong built-in electric field leading to efficient separation of the photogenerated carriers. The devices have long-term air stability and efficient switching behavior even at elevated temperatures. These high-performance and self-powered p-Sb 2 Te 3 /n-Si heterojunction photodetectors have immense potential to become reliable technological building blocks for a plethora of innovative applications in next-generation optoelectronics, silicon-photonics, chip-level sensing, and detection.

Ba 1+ x MoO 4 (-0.03 ≤ x ≤ 0.03) ceramics were fabricated by a conventional two-step sintering technique. X-ray diffraction patterns show that there appeared new diffraction peaks when x > 0, which were identified as Ba 2 MoO 5 . The Rietveld refinement results indicate that the unit cell volume is the largest at x = -0.02, because it has the lowest packing fraction and covalency. The far-infrared reflectivity (IR) spectra were fitted and analyzed for calculating the intrinsic properties, which comply well with the data obtained from microscopic polarizabilities and damping coefficient angle. The proportion of each mode in the dielectric response demonstrates that the Ba-O 8 polyhedra have a decisive role on the dielectric properties. And based on the Raman modes, the internal relations of the structural-properties were revealed with the changes of Ba 2+ content.

Pr(Mg 1/2 Sn 1/2 )O 3 (PMS) ceramic was prepared through a conventional solid-state reaction method. Crystal structure was investigated through X-ray diffraction (XRD), which certificates that the main phase is PMS with monoclinic P2 1 /n1 symmetry. Lattice vibrational modes were obtained through Raman scattering spectroscopy and Fourier transform far-infrared reflection spectroscopy. The Raman spectrum active modes were assigned and illustrated, respectively, and then fitted with Lorentzian function. The four modes within the range of 110-200 cm -1 are derived from the F 2g vibrations (A-site cations), and the other three modes (300-430 cm -1 ) are derived from the F 2g vibrations (B-site cations).The mode with highest frequency above 650 cm -1 is attributed to A 1g -like mode that corresponds to the symmetric breathing of oxygen octahedral. The far-infrared spectrum with seven infrared active modes was fitted using four-parameter semi-quantum models to calculate intrinsic properties (permittivity and loss). F 2u (2) yielded the greatest contribution to dielectric constant and loss, which is mainly performed as the inverted translational vibration of Pr-MgO 6 octahedron.