THIN-FILM SOLAR CELL

PROBLEM TO BE SOLVED: To provide a compound thin-film solar cell of high efficiency. SOLUTION: A thin-film solar cell 10 is possessed of a first layer 3 of p-type semiconductor formed of at least a compound selected from among compounds I-II-VI2 , 1-III3 -VI5 , ad I-III3 -VI8 of I, III, and VI elements in the periodic table, a second layer 4 of n-type semiconductor kept in contact with the first layer 3 and formed of at least a compound selected from among compounds III-VI, III2 -VI3 , and III6 -VI7 of III and VI elements in the periodic table, third layers 5 and 6 of n-type semiconductor kept in contact with the second layer 4 and formed of a compound II-VI of II and VI element in the periodic table, and a fourth layer 7 of n-type semicodutor formed as a transparent conductive film in contact with the third layers 5 and 6.