Articles you may be interested inMetal-induced molecular diffusion in [6,6]-phenyl-C61-butyric acid methyl ester poly(3-hexylthiophene) based bulk-heterojunction solar cells Electrical properties of pSi/[6,6] phenyl-C61 butyric acid methyl ester/Al hybrid heterojunctions: Experimental and theoretical evaluation of diode operation Addition of regiorandom poly(3-hexylthiophene) to solution processed poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester graded bilayers to tune the vertical concentration gradient Erratum: "Enhancing the photocurrent in poly(3-hexylthiophene)/ [6,6]-phenyl C61 butyric acid methyl ester bulk heterojunction solar cells by using poly(3-hexylthiophene) as a buffer layer" [Appl. Phys. Lett.95, 133303 (2009)] Appl. Phys. Lett. 95, 219902 (2009);

Both a theoretical algorithm and an experimental procedure are discussed of a new route to determine the absorption/scattering properties of thin films deposited on transparent substrates. Notably, the non-measurable contribution of the film-substrate interface is inherently accounted for. While the experimental procedure exploits only measurable spectra combined according to a very simple algorithm, the theoretical derivation does not require numerical handling of the acquired spectra or any assumption on the film homogeneity and substrate thickness. The film absorption response is estimated by subtracting the measured absorption spectrum of the bare substrate from that of the film on the substrate structure but in a non-straightforward way. In fact, an assumption about the absorption profile of the overall structure is introduced and a corrective factor accounting for the relative film-to-substrate thickness. The method is tested on films of a well known material (ITO) as a function of the film structural quality and influence of the film-substrate interface, both deliberately changed by thickness tuning and doping. Results are found fully consistent with information obtained by standard optical analysis and band gap values reported in the literature. Additionally, comparison with a conventional method demonstrates that our route is generally more accurate even if particularly suited for very thin films.

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High-level self-consistent-field calculations for a set of nitrogen-containing model molecules are carried out to study the influence on the N(1s) binding energy of first-, second-, and third-nearest neighbors, stress ͑bond angles͒, and conformation. These calculations are directed to account for the N(1s) peak structure ͑generally fit with two Gaussian functions whose centers are separated by 0.7Ϫ0.9 eV) as seen by x-ray photoemission spectroscopy at the nitrided Si-SiO 2 interface. Using a nonlinear extrapolation method to determine the core energy levels in large molecules, we have ascribed the Gaussian peak centered on (398.3Ϯ0.2) eV to nitrogen bonded to otherwise fully oxidized silicon in ''bulk'' SiO 2 and the Gaussian peak shifted by 0.7Ϫ0.9 eV toward lower binding energy to the interfacial species N͓Si(u / \ Si) 3Ϫy (Ou) y ͔ 3 with yӍ1. Not only can the observed peak be resolved in those two components, but also there is no other choice involving only nitrogen, silicon, and oxygen, which allows for the observed spectrum.

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