Semi-transparent luminescent solar concentrators window panels based on methylammonium lead bromide perovskite coatings are fabricated. It is shown that spraying as a large-scale fabrication technique delivers samples with comparable characteristics with those prepared by the physical vapor deposition or spin-coating methods. Three mirrorless, mirrored, and gaped-mirror configurations are designed for the current–voltage evaluation of the samples. According to our results, perovskite coating of glass slides with different film thickness leads to a 16% to 45% increase in the output electrical power. A gaped-mirror arrangement, through separating the bottom mirror in these devices, is introduced to mimic a typical double-glazed window panel for increasing the output efficiency. Moreover, it is demonstrated that fabricated luminescent concentrators can perform under different directional placements, which promises their widespread application in greenhouses and electrical vehicles.
The holographic optical storage capacity with photopolymer is improved by creating a multigrating onto the surface of a azopolymer thin film with the use of a liquid droplet. We show by this method that three kinds of gratings can be created and controlled by different laser beam parameters as polarization or incident angle.
Although coherent light is usually required for the self-organization of regular spatial patterns from optical beams, we show that peculiar light matter interaction can break this evidence. In the traditional method to record laser-induced periodic surface structures, a light intensity distribution is produced at the surface of a polymer film by an interference between two coherent optical beams. We report on the self-organization followed by propagation of a surface relief pattern. It is induced in a polymer film by using a low-power and small-size coherent beam assisted by a high-power and large-size incoherent and unpolarized beam. We demonstrate that we can obtain large size and well organized patterns starting from a dissipative interaction. Our experiments open new directions to improve optical processing systems. We also discuss the relevance of our experiment to other systems such as social insects, for which a self-assembly or spatial pattern is organized within a collective group, starting from amplified fluctuations.
The orientation and attachment of neuronal cells were controlled by submicron-scale topographical patterns. The surface structure is realized with a laser beam and photo-responsive azobenzene polymer thin films. A surface relief grating (SRG) can be produced by self-organization of molecules under the action of light. The cells are attached onto the SRG and preferentially grown along the groove direction. The use of polymer thin films is good candidate for cellular engineering applications.