An unprecedentedly stable CH3NH3PbI3 film synthesized by a modified chemical vapor transport method is demonstrated. The results show that the crystal structure, light absorption, and device efficiency do not degrade after storing for 100 d in air with 40% relative humidity, while the conventional solution-processed perovskites are usually stable for less than 20 d in similar conditions.

In this paper, we show for the first time that ultrafast light illumination can induce an unusually broad transient optical absorption (TA), spanning of ≈ 200 nm in the sub-bandgap region of chalcogenide GeSe2 thin films, which we interpret as being a manifestation of creation and annihilation of light induced defects. Further, TA in ultrashort time scales show a maximum at longer wavelength, h...

Efficient light absorption in thin-film photovoltaic (PV) devices is crucial for improving their efficiency and reducing cost. Here we have not only developed a low-cost and scalable method to fabricate a unique type of integrated-nanopillar-nanowell (i-NPW) structure by integrating nanopillar and nanowell arrays together vertically, but also demonstrated the attractive optical property of the ...

We present a comprehensive investigation of the charge-transfer (CT) effect in weakly interacting organic semiconductor mixtures. The donor-acceptor pair diindenoperylene (DIP) and N,N'-bis(2-ethylhexyl)-1,7-dicyanoperylene-3,4/9,10-bis(dicarboxyimide) (PDIR-CN2) has been chosen as a model system. A wide range of experimental methods was used in order to characterize the structural, optical, el...

We show an experimental and computational comparison between the resolution power, the contrast and the focal depth of a nonlinearly propagated diffraction-free beam and of other beams (a linear and a nonlinearly propagated Gaussian pulse): launching a nondiffractive Bessel pulse in a solution of Coumarine 120 in methanol creates a high contrast, 40 mm long, 10 microm width fluorescence channel...

We report what is to our knowledge the first observation of the effect of parallel-to-interface-refraction (PIR) in a three-dimensional, simple-cubic photonic-crystal. PIR is an acutely negative refraction of light inside a photonic-crystal, leading to light-bending by nearly 90 deg over broad wavelengths (λ). The consequence is a longer path length of light in the medium and an improved light ...

We report on measurements of the light absorption efficiency of InSb nanowires. The absorbed 70 fs light pulse generates carriers, which equilibrate with the lattice via electron-phonon coupling. The increase in lattice temperature is manifested as a strain that can be measured with X-ray diffraction. The diffracted X-ray signal from the excited sample was measured using a streak camera. The am...

We propose a multiple beam illumination scheme to control the intensity of the light emitted by a thin luminescent layer. The experiment is designed to get as close as possible to the condition of Coherent Perfect Absorption (CPA) at a wavelength at which the absorption coefficient of the luminescent layer is low, and it is realized by externally acting on the phase difference between the incid...

The first application of atomic absorption spectra to chemical analysis was made as long ago as 1860 by Gustav Robert Kirchhoff (1824-87), who demonstrated the presence of various elements in the solar atmosphere. Together with Robert Wilhelm Bunsen (181199), he showed shortly afterwards that atomic spectra, whether in emission or absorption, could be the basis of a powerful method of chemical ...

Since the food matrix determines β-carotene availability for intestinal absorption, food matrix effects on the bioaccessibility of β-carotene from two diets were investigated in vitro and compared with in vivo data. The "mixed diet" consisted of β-carotene-rich vegetables, and the "oil diet" contained β-carotene-low vegetables with supplemental β-carotene. The application of extrinsically label...