▎ 摘　　要

NOVELTY - The cell (600) has a set of upper and lower photovoltaic layers (610, 630) formed on a rear electrode (680) and a set of front electrodes arranged on a front surface of one of the photovoltaic layers. A transparent subsidiary electrode (690) is placed on the front surface of the photovoltaic layer and a front surface of the front electrodes, where the transparent subsidiary electrode is made of graphene. A concentrating unit concentrates incident light and provides the concentrated light to the photovoltaic layer, where a concentration ratio of the concentrating unit is equal to or greater than 180. USE - Solar cell ADVANTAGE - The subsidiary electrode is made of grapheme to reduce resistance against current transportation to increase a fill factor and efficiency, and to create a set of various moving paths of charge carriers such as electrons, thus improving a current flow to improve power generation efficiency of the cell. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a solar cell. Solar cell (600) Upper and lower photovoltaic layers (610, 630) Substrate (640) Rear electrode (680) Transparent subsidiary electrode (690)