For intermediate-band solar cells, the broad absorption spectrum of quantum dots (QDs) offers a favorable conversion efficiency, and photocurrent generation via efficient two-step two-photon-absorption (TS-TPA) in QDs is essential for realizing high-performance solar cells. In the last decade, many works were dedicated to improve the TS-TPA efficiency by modifying the QD itself, however, the ob...

Using high-intensity femtosecond pulses at l5264 nm, we have measured the two-photon absorption ~TPA! coefficient in three fused silica samples Suprasil, Herasil, Infrasil ~Heraeus! and in 3.5 mol % Ge-doped fused silica. While in fused silica samples the TPA coefficient value is about 2310 cm/W, in germanosilicate glass it equals (4263)310 cm/W. © 2002 American Institute of Physics. @DOI: 10.1...

A theoretical analysis of linear and non-linear (two-photon absorption) electronic spectroscopy of all known porphyrinic pigments has been performed using linear and quadratic density functional response theory, with the long-range corrected CAM-B3LYP functional. We found that higher Soret transitions often contain non-Gouterman contributions and that each chlorophyll has the possibility for re...

Abstract The compositional effect of Mo/W ratio on linear, nonlinear absorption and optical limiting behavior the NaBi(Mo x W 1−x O 4 ) 2 single crystals grown by Czochralski technique was investigated. X-ray diffraction patterns studied presented well-defined peaks associated with tetragonal crystalline structure. performance threshold were determined using an open-aperture Z-scan technique. A...

human body consists of some tissues among which bone is one of the important living and growing tissue . in this research, energy absorption buildup factor (eabf) values of 27 types of bone have been computed for photon energy 0.03 to 1.5 mev up to 40 mean free path (40mfp) penetration depths. the inner bone tissue, spongiosa and male sternum had the largest values of eabf in low photon energie...

objective(s): in this study we evaluate the impact of the different aspects of gold nano-particles (gnps) on the target absorptive dose enhancement factor (def) during external targeted radiotherapy with photon beams ranging from kilovolt to megavolt energies using monte carlo simulation. methods: we have simulated the interaction of photon beams with various energies of radiation using water s...

Availability, ease of use, relative low cost, and minimal radiation exposure have made dual-energy x-ray absorptiometry the most widely used technique worldwide to obtain bone measurements for both research and clinical purposes in pediatric populations. However, errors related to growth and maturity significantly diminish the accuracy of dual-energy x-ray absorptiometry bone measurements. Seve...

Photodynamic therapy (PDT) leads to cell death by using a combination of a photosensitizer and an external light source for the production of lethal doses of reactive oxygen species (ROS). Since a major limitation of PDT is the poor penetration of UV-visible light in tissues, there is a strong need for organic compounds whose activation is compatible with near-infrared excitation. Triphenylamin...