Organic thin-film solar cell and organic thin-film solar cell manufacturing method

Abstract

Provided is an organic thin-film solar cell, including: a substrate, an anode, an organic thin-film layer that includes an organic semiconductor layer, and a cathode. The anode, the organic thin-film layer that includes the organic semiconductor layer, and the cathode are layered in order on top of the substrate. A recess and protrusion-shaped microstructure that includes a plurality of recesses or protrusions arranged two-dimensionally at random is formed in an interface between the organic thin-film layer and the cathode. The recess and protrusion-shaped microstructure is formed such that, when λand λare a shorter wavelength and a longer wavelength, respectively, of wavelengths that produce an absorption edge in a light absorption spectrum of the organic semiconductor layer, and kand kare real parts of propagation constants of surface plasmons that correspond, respectively, to those wavelengths and occur along an interface between the organic semiconductor layer and the cathode, and when the real part kcorresponds to an upper wavenumber limit Kin a power spectrum of a height distribution of the microstructure formed in the interface between the cathode and the organic semiconductor layer, and the real part kcorresponds to a lower wavenumber limit Kin the power spectrum of the height distribution of the microstructure formed in the interface between the cathode and the organic semiconductor layer, the power spectrum of the height distribution of the microstructure exhibits determinate values between the upper wavenumber limit Kand the lower wavenumber limit K, and an integrated value of a spectral intensity of the power spectrum of the height distribution over a wavenumber range from Kto Kis equal to at least 50% of an integrated value of the spectral intensity of the power spectrum of the height distribution across all wavenumbers.