应用物理
Metasurfaces enable efficient manipulation of electromagnetic radiation. In particular, control over plane-wave reflection is one of the most useful features in many applications. Extensive research has been done in the field of anomalous…
Metastable defects can decisively influence the diode factor and thus the efficiency of a solar cell. The diode factor is also influenced by the doping level and the recombination mechanisms in the solar cell. Here we quantify how the…
Copper indium disulfide (CuInS$_2$) grown under Cu-rich conditions exhibits high optical quality but suffers predominantly from charge carrier interface recombination resulting in poor solar cell performance. An unfavorable cliff like…
The paper considers a model for the solar cell as a mechanical open-cycle thermodynamic engine where the chemical potential is produced in an isochoric process corresponding to the thermalization of electron-hole pairs. Expansion of the…
A particle on a substrate supporting a surface acoustic wave can experience horizontal drift excited by the dry friction force. The effect is referred to as vibrational transportation, or as a surface acoustic wave motor. A traditional…
Terahertz (THz) frequency combs (TFCs) are promising for numerous applications in spectroscopy, metrology, sensing, and wireless communications. However, the practical applications of TFCs have been hindered thus far by the need for…
The need for high-temperature piezoelectric microelectromechanical systems (MEMS) requires pushing piezoelectric platforms to their thermal limits. In harsh thermal environments, piezoelectric MEMS devices are expected to sustain severe…
Characterizing intrinsic defects is an important step in evaluating materials for new optoelectronic device applications. For photomultipliers, suppressing dark currents is critical, but there exists a tradeoff between maximizing the band…
Broadband longitudinal-to-transverse mode conversion under normal incidence remains difficult to achieve, especially with structurally simple designs. Numerical simulations show that a single periodic row of inclined long-slits near a free…
The next generation of technology is rooted in quantum-based advancements. The entangled photon pair sources play a pivotal role in such wide range of advancement in quantum-based applications, including quantum high precision sensors,…
Control of thermal emission is important in a number of applications from thermal energy harvesting and management and sensing of gas and chemical to thermal camouflage. Semiconductor-based devices can be engineered to enable electrical…
High-fidelity shock experiments were performed on copper powders with controlled porosity via improved target fabrication and assembly. Optical velocimetry and multi-channel pyrometry were used to obtain Hugoniot data, isentropic release…
This study identified the key design factors related to thermal comfort in naturally ventilated underground spaces under high temperature conditions (outdoor Tmax = 42.9 C) in Fuzhou, China. Fuzhou has a humid subtropical climate and is one…
The torsional vibration of atomic force microscope (AFM) cantilevers is critical for high-sensitivity measurements, yet existing models for width-varying cantilevers often rely on approximations that lead to significant discrepancies with…
In this work, we demonstrate the first two-port radial-mode Rosen transformer based on 36$^{\circ}$Y-cut lithium niobate (LN) for piezoelectric power conversion. The device achieves a high transformation ratio (TF) of 16, a high…
Driven by growing demand for clean energy, triboelectric nanogenerators (TENGs) have emerged as promising self-powered systems, yet achieving high charge density remains a critical challenge. In polymer dielectrics, triboelectricity can be…
Here, we report the first experimental demonstration of InN nanowire solar cells deposited by RF sputtering with a bandgap energy of 1.78 eV. By adding an amorphous Si (a-Si) buffer to the n-InN/p-Si structure, we have improved the…
The natural source of a magnetic dipole in antennas is typically an electrically small loop, which can be utilized in conjunction with an electric dipole to realize an electrically small Huygens' antenna. However, these antennas suffer from…
The emergence of high-repetition-rate x-ray free-electron lasers, such as SLAC's LCLS-II, serve as our canonical example for autonomous controls that necessitate high-throughput diagnostics paired with streaming computational pipelines…
This paper shows a fundamental thermodynamic similarity between thermoelectric and photovoltaic energy converters which, at open circuit, can be represented as isochoric engines generating a finite chemical potential which appears as…