Abstract: A photovoltaic structure including a nanocone-based three-dimensional interdigitated p-n junction is provided in the present invention. The three-dimensional p-n junction is at the interface between n-type oxide semiconductor nanocones and a p-type semiconductor material that functions as a matrix embedding the nanocones. The nanocone-based three-dimensional p-n junction allows efficient minority carriers being extracted from photo-absorber and crossing across the p-n junction, and generates completely-depleted regions throughout the nanocones and the matrix around the nanocones for efficient charge collection. Further, the bandgap energies of the p-doped semiconductor material can be tuned to match the solar light spectrum by mixing related elements. Further, the high temperature pulses can be used to remove defects in the junction interfaces and sintering nanoparticle matrix.

Abstract: A method for the direct measurement of large strains in ropes in situ using a plastic optical fiber, for example, perfluorocarbon or polymethyl methacrylate and Optical Time-Domain Reflectometer or other light time-of-flight measurement instrumentation. Protective sheaths and guides are incorporated to protect the plastic optical fiber. In one embodiment, a small rope is braided around the plastic optical fiber to impose lateral compressive forces to restrain the plastic optical fiber from slipping and thus experience the same strain as the rope. Methods are described for making reflective interfaces along the length of the plastic optical fiber and to provide the capability to measure strain within discrete segments of the rope. Interpretation of the data allows one to calculate the accumulated strain at any point in time and to determine if the rope has experienced local damage.