Composite comprising array of needle-like crystal, method for producing the same, photovoltaic conversion element, light emitting element, and capacitor

摘要

A composite of a base and an array of needle-like crystals formed on a surface of the base is provided, in which the base side and the opposite side to the base with respect to the array can be isolated in a satisfactory manner. A composite 10 contains a transparent electrode 2 serving as the base and an array 4 of needle-like crystals 3 formed thereon. The needle-like crystals 3 are made of, for example, zinc oxide. The array 4 includes a first region R1 on the transparent electrode 2 side and a second region R2 on the opposite side to the transparent electrode 2 with respect to the first region R1. A proportion of the cross section of the needle-like crystals 3 in a plane parallel to the surface of the transparent electrode 2 is lower in the second region R2 than in the first region R1, and the surface of the transparent electrode 2 is substantially covered with the needle-like crystals 3 in the first region R1.