LIGHT EXTRACTION TRANSPARENT SUBSTRATE FOR ORGANIC ELECTROLUMINESCENT ELEMENT AND ORGANIC ELECTROLUMINESCENT ELEMENT USING SAME

摘要

A light extraction transparent substrate for an organic EL element, which is used by being disposed on an emitting surface side of light (L) in the organic EL element, the light extraction transparent substrate comprising:
a transparent supporting substrate (10);
a diffraction grating (11) which comprises a first concavity and convexity layer having first concavities and convexities formed on a surface thereof and which is located on a surface of the transparent supporting substrate (10), the surface serving as an incident surface (10A) of the light (L) of the organic EL element when the transparent supporting substrate (10) is used in the organic EL element; and
a microlens (12) which comprises a second concavity and convexity layer having second concavities and convexities formed on a surface thereof and which is located on a surface of the transparent supporting substrate (10), the surface serving as an emitting surface (10B) of the light (L) of the organic EL element when the transparent supporting substrate (10) is used in the organic EL element, wherein
a shape of the first concavities and convexities and a shape of the second concavities and convexities are each such that when a Fourier-transformed image is obtained by performing two-dimensional fast Fourier transform processing on a concavity and convexity analysis image obtained by analyzing the shape of the concavities and convexities by use of an atomic force microscope, the Fourier-transformed image shows a circular or annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 µm -1 .