Abstract: A method of manufacturing a solar cell that includes forming a first electrode on a substrate, forming a first thin film including a Group III-VI compound on the first electrode, forming a second thin film including a Group I-III compound on the first thin film, forming a third thin film including a Group III element on the second thin film, heat-treating the first thin film, the second thin film, and the third thin film under a gas atmosphere containing a Group VI element to form a photoactive layer, and forming a second electrode on the resulting photoactive layer, wherein the first thin film and the third thin film include the same Group III element, and the second thin film includes a Group III element that is different from the Group III element of the first thin film and the third thin film.

Abstract: A solar cell in which the P-type light absorbing layer is thin, and the nanoparticles are disposed. Although the P-type light absorbing layer is thin, the light absorption efficiency may be increased by the use of nanoparticles. Accordingly, the P-type light absorbing layer is formed thin, and thereby the material cost may be reduced and the process time may be shortened. Also, a solar cell in which the nanoparticles are disposed on the transparent electrode layer or inside the transparent electrode layer, and the size of the nanoparticles and the space between them are controlled such that the light absorption efficiency may be increased, and the nanoparticles are disposed in the N-type light absorbing layer, and the size of the nanoparticles and the space between them are controlled such that the light absorption efficiency may be increased.