Weak intrinsic charge transfer complexes: A new route for developing wide spectrum organic photovoltaic cells

Solar emission extends in the near IR and one of the main issues in designing organic solar cells resides in extending the response into the near IR. Here we show that this may be achieved by making intimate interpenetrated networks of C60 and Zn-phthalocyanine (Zn-Pc) in the solid. Various spectroscopic investigations of co-sublimated thin films of C60 and Zn-phthalocyanine give indeed ample evidence of the existence of a weak charge transfer (CT) state at 1.4 eV, which quenches the photoluminescence of both molecules. The films produced by co-sublimation undergo to a spinodal decomposition producing domains prevalently constituted by Zn-Pc in contact with domain prevalently of C60. The domains size depends on the deposition conditions (rate, stoichiometry, and substrate temperature) forming a percolating 3D network. The separation in different domains is confirmed by the observation of two overlapping peaks, in the resonant Raman spectrum, that correspond to the Ag(2) pinch mode (C=C double bond stretching) for pristine C60 and for a partially (~0.25e) doped one. This indicates that only those donor molecules at the grain boundary, which are in contact with C60, give rise to a renormalized new CT ground state. Photocurrent measurements of interpenetrated networks of C60 and Zn-Pc show a linear dependence with respect to the incident light as a consequence of direct absorption within the CT state. The CT state favors the charge separation between the two components, when it is inserted as interface in the organic photovoltaic p - n junction thus increasing the efficiency of the device

Realistic fluids as source for dynamically accreting black holes in a cosmological background

We show that a single imperfect fluid can be used as a source to obtain the generalized McVittie metric as an exact solution to Einstein's equations. The mass parameter in this metric varies with time thanks to a mechanism based on the presence of a temperature gradient. This fully dynamical solution is interpreted as an accreting black hole in an expanding universe if the metric asymptotes to Schwarzschild-de Sitter at temporal infinity. We present a simple but instructive example for the mass function and briefly discuss the structure of the apparent horizons and the past singularity.Comment: 5 pages, 2 figures. Updated references and minor changes to match the version accepted for publishing in PR

The Contribution of the Smectic-Nematic Interface to the Surface Energy

The contribution of the smectic-nematic interface to the surface energy of a nematic liquid crystal sample is analyzed. By means of a simple model it is shown that the surface energy depends on the thickness of the region over which the transition smectic-nematic takes place. For perfectly flat substrates this thickness is of the order of the correlation length entering in the transition. An estimate of this contribution shows that it is greater than the one arising from the nematic-substrate interaction. Moreover, it is also shown that the surface energy determined in this way presents a non-monotonic behavior with the temperature.Comment: 10 pages, revte

Response to erlotinib in a patient with lung adenocarcinoma harbouring the EML4-ALK translocation: A case report.

Lung cancer is the leading cause of cancer-associated mortality worldwide, and the mainstay of treatment remains to be personalised therapy. Tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have been reported to exert a significant impact in the treatment of non-small cell lung cancer (NSCLC), particularly in patients harbouring mutations in the EGFR gene. The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) gene translocation has been described in a subset of patients with NSCLC and possesses potent oncogenic activity. This translocation represents one of the most novel molecular targets in the treatment of NSCLC. Patients who harbour the EML4-ALK rearrangement possess lung tumours that lack EGFR or K-ras mutations. The present study reports the case of a patient possessing the EML4-ALK rearrangement that was initially treated with erlotinib and achieved a lasting clinical response. To the best of our knowledge, the current study is the first report of a clinical response to EGFR-TKI in a patient with lung adenocarcinoma harbouring the EML4-ALK fusion gene, but no EGFR mutations. However, as the disease progressed, the ALK gene status of the tumour was investigated, and based upon a positive result, the patient was treated with crizotinib and achieved a complete response. In conclusion, the present study suggests that the EML4-ALK rearrangement is not always associated with resistance to EGFR-TKIs. Further studies are required to clarify the biological features of these tumours and to investigate the mechanisms underlying the primary resistance to EGFR-TKIs when the EML4-ALK rearrangement is present

Self-consistency in Theories with a Minimal Length

The aim of this paper is to clarify the relation between three different approaches of theories with a minimal length scale: A modification of the Lorentz-group in the 'Deformed Special Relativity', theories with a 'Generalized Uncertainty Principle' and those with 'Modified Dispersion Relations'. It is shown that the first two are equivalent, how they can be translated into each other, and how the third can be obtained from them. An adequate theory with a minimal length scale requires all three features to be present.Comment: typos corrected, published with new title following referee's advic