相关论文: First principles calculation of shift current in c…
Recently, it has been shown how shift and ballistic currents in piezoelectric sillenite crystals Bi$_{12}$GeO$_{20}$ and Bi$_{12}$SiO$_{20}$ can be separated experimentally under the assumption that the shift component of the circular…
The bulk photovoltaic effect (BPVE) occurs in solids with broken inversion symmetry and refers to DC current generation due to uniform illumination, without the need of heterostructures or interfaces, a feature that is distinct from the…
The circular photon drag effect is observed in a bulk semiconductor. The photocurrent caused by a transfer of both translational and angular momenta of light to charge carriers is detected in tellurium in the mid-infrared frequency range.…
A linearly polarized light normally incident on a semiconductor quantum well with spin-orbit coupling may generate pure spin current via direct interband optical transition. An electric photocurrent can be extracted from the pure spin…
We present a theoretical study of the shift current in a noncentrosymmetric polytype of graphitic BC$_2$N. We find that the photoconductivity near the fundamental gap is strongly anisotropic due to the vanishing of particular tensor…
A spin current has novel linear and second-order nonlinear optical effects due to its symmetry properties. With the symmetry analysis and the eight-band microscopic calculation we have systematically investigated the interaction between a…
Ferroelectrics with suitable band gaps have recently attracted attention as candidate solar absorbing materials for photovoltaics. The inversion symmetry breaking may promote the separation of photo-excited carriers and allow voltages…
Shift current is a DC current generated from nonlinear light-matter interaction in a non-centrosymmetric crystal and is considered a promising candidate for next generation photovoltaic devices. The mechanism for shift currents in real…
DC photoelectrical currents can be generated purely as a non-linear effect in uniform media lacking inversion symmetry without the need for a material junction or bias voltages to drive it, in what is termed photogalvanic effect. These…
We have studied theoretically the Weyl semimetals the point symmetry group of which has reflection planes and which contain equivalent valleys with opposite chiralities. These include the most frequently studied compounds, namely the…
The theory of the shift current is thus far geometrical without being topological. This means that the real-space displacement/shift of a photoexcited quasiparticle depends on the geometric Berry phase, but the Berry phase is not quantized…
We elucidate light-induced orbital and spin current through nonlinear response theory, which generalizes the well-known bulk photovoltaic effect in centrosymmetric broken materials from charge to the spin and orbital degrees of freedom. We…
While the basic principles and limitations of conventional solar cells are well understood, relatively little attention has gone toward maximizing the potential efficiency of photovoltaic devices based on shift currents. In this work, we…
Designing materials with controlled photovoltaic response may lead to improved solar cells or photosensors. In this regard, ferroelectric superlattices have emerged as a rich platform to engineer functional properties. In addition,…
The correlation between the shift current mechanism for the bulk photovoltaic effect (BPVE) and the structural and electronic properties of ferroelectric perovskite oxides is not well understood. Here, we study and engineer the shift…
The two-dimensional (2D) bulk photovoltaic effect (BPVE) is a cornerstone for future highly efficient 2D solar cells and optoelectronics. The ferromagnetic semiconductor 2H-FeCl2 is shown to realize a new type of BPVE in which spatial…
Photocurrent in solids is an important phenomenon with many applications including the solar cells. In conventional photoconductors, the electrons and holes created by light irradiation are separated by the external electric field,…
The connection between noncentrosymmetric materials' structure, electronic structure, and bulk photovoltaic performance remains not well understood. In particular, it is still unclear which photovoltaic (PV) mechanism(s) are relevant for…
Although the absorption of light in a bulk homogeneous semiconductor produces photocarriers with non-zero momentum, it generally does not produce a current in the absence of an applied electric field because equal amounts of carriers with…
Bulk photovoltaic effect, which arises from crystal symmetry-driven charge carrier separation, is an intriguing physical phenomenon that has attracted extensive interest in photovoltaic application due to its junction-free photovoltaic and…