Approach for predicting and adjusting the pointing accuracy of opto-mechanical systems considering multi-source uncertainty.

Pointing accuracy is a critical performance indicator of opto-mechanical systems, directly affecting the systems' efficiency and application range. This study introduces what we believe to be a novel approach for predicting pointing accuracy and adjusting processes in opto-mechanical systems, considering multi-source uncertainty quantification. First, the relationship between error components and total error is quantified using homogeneous coordinate transformation theory.

Reconstruction and Solidification of Dion-Jacobson Perovskite Top and Buried Interfaces for Efficient and Stable Solar Cells.

Quasi-two-dimensional (Q-2D) perovskites show great potential in the field of photonic and optoelectronic device applications. However, defects and local lattice dislocation still limit performance and stability improvement by nonradiative recombination, unpreferred phase distribution, and unbonded amines. Here, a low-temperature synergistic strategy for both reconstructing and solidifying the perovskite top and buried interface is developed.

Dynamical Symmetry-Reduction-Induced Giant Anharmonicity in IV-VI Compounds: Role of Cation Lone-Pair Electrons.

The low thermal conductivity of group IV-VI semiconductors is often attributed to the soft phonons and giant anharmonicity observed in these materials. However, there is still no broad consensus on the fundamental origin of this giant anharmonic effect. Utilizing first-principles calculations and group symmetry analysis, we find that the cation lone-pairs electrons in IV-VI materials cause a significant coupling between occupied cation orbitals and unoccupied cation orbitals due to the symmetry reduction when atoms vibrate away from their equilibrium positions under heating.

The six-degrees-of-freedom attitude measurement instrument for the large aperture mirror using the prepressing sensors and flexible supporting.

To achieve precise measurement of a large aperture mirror, a six-degrees-of-freedom (6-DOF) measurement instrument is designed to monitor and calculate the real-time attitude of the mirror. Magnetoelectric displacement sensors are prepressed, and a flexible sensor supporting is designed to achieve high-accuracy measurement. The relationship between 6-DOF displacements of the mirror and the six sensor values can be obtained using the coordinate system transformation and Jacobian matrix.

Band offset trends in IV-VI layered semiconductor heterojunctions.

The band offsets between semiconductors are significantly associated with the optoelectronic characteristics and devices design. Here, we investigate the band offset trends of few-layer and bulk IV-VI semiconductors MX and MX(M = Ge, Sn; X = S, Se, Te). For common-cation (anion) systems, as the atomic number increases, the valence band offset of MX decreases, while that of MXhas no distinct change, and the physical origin can be interpreted using band coupling mechanism and atomic potential trend.

Decoupling of the Electrical and Thermal Transports in Strongly Coupled Interlayer Materials.

Thermoelectric materials which enable heat-to-electricity conversion are fundamentally important for heat management in semiconductor devices. Achieving high thermoelectric performance requires blocking the thermal transport and maintaining the high electronic transport, but it is a challenge to satisfy both criteria simultaneously. We propose that tuning the interlayer distance can effectively modulate the electrical and thermal conductivities.

Phonon-driven electron scattering and magnetothermoelectric effect in two-dimensional tin selenide.

The bulk tin selenide (SnSe) is the best thermoelectric material currently with the highest figure-of-merit due to strong phonon-phonon interactions. We investigate the effect of electron-phonon coupling (EPC) on the transport properties of a two-dimensional (2D) SnSe sheet. We demonstrate that EPC plays a key role in the scattering rate when the constant relaxation time approximation is deficient.

Classical to quantum transition of heat transfer between two silica clusters.

Heat transfer between two silica clusters is investigated by using the nonequilibrium Green's function method. In the gap range between 4 Å and 3 times the cluster size, the thermal conductance decreases as predicted by the surface charge-charge interaction. Above 5 times the cluster size, the volume dipole-dipole interaction predominates.

Thermal transport in hexagonal boron nitride nanoribbons.

The thermal transport properties of hexagonal boron nitride nanoribbons (BNNRs) are investigated. By calculating the phonon spectrum and thermal conductance, it is found that the BNNRs possess excellent thermal transport properties. The thermal conductance of BNNRs can be comparable to that of graphene nanoribbons (GNRs) and even exceed the latter below room temperature.