This work describes the fabrication and characterization of an improved version of large area (5mm×80mm with an active length of 70mm) flexible position sensitive detectors deposited onto polymeric substrates (polyimide-Kapton® VN). The new configuration presented by the sensor is based on a heterostructure of a-Si:H/ZnO:Al. The sensors were characterized by spectral response, photocurrent dependence as a function of light intensity and position detection measurements. The set of data obtained on one-dimensional position sensitive detectors based on the heterostructure show excellent performances with a maximum spectral response of 0.12A/W at 500nm and a non-linearity of ±10% over 70mm length. The produced sensors present a non-linearity higher than those ones produced on glass substrates, due to the different thermal coefficients exhibited by the polymer and the amorphous silicon film. In order to prove this behaviour, it was measured the defect density obtained by the constant photocurrent method on amorphous silicon deposited on polymeric substrates bended with different radius of curvature. © 2004 Elsevier B.V. All rights reserved.

n/a

We prove necessary conditions for the Fredholmness of singular integral operators with piecewise continuous coefficients on weighted Banach function spaces. These conditions are formulated in terms of indices of submultiplicative functions associated with local properties of the space, of the curve, and of the weight. As an example, we consider weighted Nakano spaces \(L^{p(\cdot)}_w\) (weighted Lebesgue spaces with variable exponent). Moreover, our necessary conditions become also sufficient for weighted Nakano spaces over nice curves whenever \(w\) is a Khvedelidze weight, and the variable exponent \(p(t)\) satisfies the estimate \(|p(\tau)-p(t)|\le A/(-\log|\tau-t|)\).

n/a

Doped a/μc-Si:H films were produced in different starting deposition conditions by the hot wire chemical vapor deposition technique. In this paper, we show that by changing the initial onset deposition conditions of the process and maintaining the overall pressure, hydrogen dilution and filament temperature, it is possible to control the compactness of the films. As the films nucleation is the key parameter to produce compact films, we show that starting the process with hydrogen and progressively introducing the process gas enhances the compactness and improve the electrical properties of the films produced. © 2002 Elsevier Science B.V. All rights reserved.