Provided is a photovoltaic device with an organic buffer layer for efficiency improvement. The photovoltaic device includes a first electrode and a second electrode disposed opposite to each other, a photoactive layer disposed between the first electrode and the second electrode, and a buffer layer disposed between the photoactive layer and the second electrode. The buffer layer includes a compound including an aromatic organic cation and an anion in a quantity ranging from 30 wt % to 100 wt %, more preferably 50 wt % to 100 wt % with respect to the entire weight of the buffer layer.