Concept for Efficient Light Harvesting in Perovskite Materials via Solar Harvester with Multi-Functional Folded Electrode

Conventional electrodes in typical photodetectors only conduct electrical signals and introduce high optical reflection, impacting the optical-to-electrical conversion efficiency. The created surface solar harvester with a multi-functional folded electrode (MFFE) realizes both a three-dimensional Schottky junction with a larger light detecting area as well as low optical reflection from 300 nm (ultra-violet light) to 1100 nm (near-infrared light) broadly without an additional anti-reflection layer. The MFFE needs silicon etching following the lithography process. The metal silver was deposited over structured silicon, completing the whole device simply. According to the experimental results, the width ratio of the bottom side to the top side in MFFE was 15.75, and it showed an optical reflection of 5–7% within the major solar spectrum of AM1.5G by the gradient refractive index effect and the multi-scattering phenomenon simultaneously. While the perovskite materials were deposited over the MFFE structure of the solar harvester, the three-dimensional electrode with lower optical reflection benefitted the perovskite solar cell with a larger detecting area and an additional anti-reflection function to absorb solar energy more efficiently. In this concept, because of the thin stacked film in the perovskite solar cell, the solar energy could be harvested by the prepared Schottky junction of the solar harvester again, except for the optical absorption of the perovskite materials. Moreover, the perovskite materials deposited over the MFFE structure could not absorb near-infrared (NIR) energies to become transparent. The NIR light could be harvested by the light detecting junction of the solar harvester to generate effective photocurrent output additionally for extending the detection capability of perovskite solar cell further. In this work, the concept of integration of a conventional perovskite solar cell with a silicon-based solar harvester having an MFFE structure was proposed and is expected to harvest broadband light energies under low optical reflection and enhance the solar energy conversion efficiency.

Study of Ar+ and He+ implanted SOS-structures

In the work Silicon – on - insulator nanostructures after implantation by various doses of ions 4He+ and 40Ar+ are investigated. Researches were carried out by measurement of optical reflection spectrum and magnitude of work function of an electron. It is shown that ions 40Ar+ in Silicon – on - insulator nanostructures, providing high efficiency of gettering influence, incorporate the neutral divacancy responsible for an observable minimum in ranges of reflection 0.73-0.75eV. As a result of implanted by ions 4He+ the gettering doesn’t occur and the entered defects are divacancies with one negative charge, responsible for an observable maximum in reflection ranges 0.73-0.75eV. The received results indicate possibility of purposeful updating of Silicon – on - insulator nanostructures for improvement of their optical characteristics. Start your abstract here… The abstract should include the purpose of research, principal results and major conclusions. References should be avoided, if it is essential, only cite the author(s) and year(s) without giving reference list. Prepare your abstract in this file and then copy it into the registration web field.

The carbon components in indoor and outdoor PM2.5 in winter of Tianjin

To study the carbon components in indoor and outdoor PM2.5, the samples of PM2.5 were collected from Nankai University in December 2015. The contents of eight carbon components were analyzed to use the thermo-optical reflection method. The results indicated that organic carbon (OC) mass concentration was 17.01, 19.48 and 18.92 µg/m3 in outdoor, dormitory and laboratory; elemental carbon (EC) mass concentration was 7.97, 3.56 and 3.53 µg/m3 in outdoor, dormitory and laboratory; and the total carbon aerosol was the proportion of more than 23% of PM2.5 samples. Lower wind speed and higher relative humidity were helpful to the accumulation of PM2.5. The ratio of OC/EC was > 2, and the SOC/OC ratio was > 30%, indicating that SOC was a crucial component indoors and outdoors. About 72% and 85% of the outdoor OC entering dormitory and laboratory environment, and about 59% and 71% of the outdoor EC entering dormitory and laboratory environment. Factor analysis of the eight carbon fractions indicated that the sources of OC and EC in outdoor, dormitory and laboratory is different.

Devotional Reflections by Marvellous Mirrors

Jan David’s Duodecim specula (Antwerp: Officina Plantiniana, 1610) is a meditative emblem book, centred around myriad mirror metaphors. However, it also contains various depictions of ‘real’ optical instruments, such as lenses and concave mirrors, which have not yet been studied as such. This article explores how catoptrics and dioptrics (optical reflection and refraction) inform the meditative programme laid out in Duodecim specula. In the emblems and text, it will be argued, Jan David relies on a type of public knowledge of optics, which he expected the reader to possess. By tapping into this reservoir of optical knowledge and adding onto it, the book stimulates the affective reading process and hands the reader concrete tools for performing the meditative programme.

OPTICAL ANISOTROPY AND BIREFRINGENCE OF CuAlS2 CRYSTALS

Optical spectra were investigated in a spectral range of (300 - 700) nm for CuAlS2 single crystals. Transmission and wavelength modulated transmission spectra demonstrated presence of some impurity absorption bands in the region of optical transparency of crystals. Optical functions (real and imaginary components of the dielectric function, refractive index and extinction coefficient) have been calculated from the optical reflection spectra by means of the Kramers-Kronig relations. A strong anisotropy and birefringence have been revealed for CuAlS2 crystals. Two isotropic points have been found in (100) oriented platelets around 380 nm and 530 nm. The position of the isotropic point around 530 nm was found to be strongly influenced by the technological conditions of crystal growth and platelet thickness, it being situated at 535 nm for a platelet with thickness of 223 µm. An optical band-pass filter was constructed with such a platelet placed between two Gran-Thompson prism crossed polarizers.