Related papers: Highly nonlinear biexcitonic photocurrent from ult…
We present a comprehensive optical study of thin films of tungsten disulfide (WS$_2$) with layer thicknesses ranging from mono- to octalayer and in the bulk limit. It is shown that the optical band-gap absorption of monolayer WS$_2$ is…
An excitonic insulator phase is expected to arise from the spontaneous formation of electron-hole pairs (excitons) in semiconductors where the exciton binding energy exceeds the size of the electronic band gap. At low temperature, these…
We investigate the excitonic transitions in single- and few-layer MoSe2 phototransistors by photocurrent spectroscopy. The measured spectral profiles show a well-defined peak at the optically active (bright) A0 exciton resonance. More…
The monolayer transition metal dichalcogenides are an emergent semiconductor platform exhibiting rich excitonic physics with coupled spin-valley degree of freedom and optical addressability. Here, we report a new series of low energy…
We discuss the conditions under which the predicted (but not yet observed) zero-field interlayer excitonic condensation in double layer graphene has a critical temperature high enough to allow detection. Crucially, disorder arising from…
Photocurrent is arising as a powerful tool for detecting in-plane collective excitations in hybrid polariton systems. In this paper, based on the intrinsic optoelectric response of graphene, photocurrent imaging of in-plane plasmons from…
We investigate excitonic transitions in a h-BN encapsulated monolayer $\textrm{MoS}_2$ phototransistor by photocurrent spectroscopy at cryogenic temperature (T = 5 K). The spectra presents excitonic peaks with linewidths as low as 8 meV,…
Multi-photon absorption processes have a nonlinear dependence on the amplitude of the incident optical field i.e. the number of photons. However, multi-photon absorption is generally weak and multi-photon events occur with extremely low…
Unravelling the nature of energy transport in multi-chromophoric photosynthetic complexes is essential to extract valuable design blueprints for light-harvesting applications. Long-range exciton transport in such systems is facilitated by a…
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…
Few-layer black phosphorus, a new elemental 2D material recently isolated by mechanical exfoliation, is a high-mobility layered semiconductor with a direct bandgap that is predicted to strongly depend on the number of layers, from 0.35 eV…
Advances in manipulating the structure of optical beams enable the study of interaction between structured light and low-dimensional semiconductor systems. We explore the photocurrents in two-dimensional systems excited by such…
Atomically thin two-dimensional (2D) semiconductors are extensively investigated for opto-electronic applications that require strong light-matter interactions. In view of such applications, it is essential to understand how…
Monolayers of transition metal dichalcogenides are semiconducting materials which offer many prospects in optoelectronics. A monolayer of molybdenum disulfide (MoS2) has a direct bandgap of 1.88 eV. Hence, when excited with optical photon…
We show that recently observed DC currents produced by below-the-bandgap femtosecond pulses [1] can be explained as nonlinear optical effects based on multi-photon quantum interference and creation of an asymmetric distribution of virtual…
The high flexibility of organic molecules offers great potential for designing the optical properties of light-active materials for the next generation of optoelectronic and photonic applications. However, despite successful implementations…
Layered van der Waals materials offer novel opportunities for on-chip waveguiding and development of integrated photonic circuits. In the strong light-matter coupling regime, their nonlinear response can be significantly enhanced, which is…
Optical driving of materials has emerged as a versatile tool to control their properties, with photo-induced superconductivity being among the most fascinating examples. In this work, we show that light or lattice vibrations coupled to an…
We show that when a monopolar current is passed through an n-i-n structure, superlinear photocurrent response occurs when there is a polariton condensate. This is in sharp contrast to the previously observed behavior for a standard…
Compact optical detectors with fast binary photoswitching over a broad range of wavelength are essential as an interconnect for any light-based parallel, real-time computing. Despite of the tremendous technological advancements yet there is…