Organic solar cells with remarkable enhanced efficiency by using a CuI buffer to control the molecular orientation and modify the anode

CuI is used to control the molecular orientation of copper phthalocyanine (CuPc) and modify the anodes in organic solar cells based on $CuPc/C60$⁠. By introducing a CuI buffer between indium tin oxide and CuPc, the power conversion efficiency is significantly enhanced by a factor of $∼70%$⁠. Because of the strong interactions between the CuI and CuPc, the stacking orientation of CuPc molecules is changed, resulting in a $∼65%$ increase in absorption coefficient, a larger carrier mobility and a smoother film surface. The anode work function is raised by the formation of a dipole layer.