Organic thin-film solar cell based on three emitting layers and preparing method thereof

The invention discloses an organic thin-film solar cell based on three emitting layers and a preparing method thereof. The organic thin-film solar cell is of a regular structure and sequentially comprises a transparent substrate, a transparent positive electrode, a positive electrode decorating layer, a first emitting layer, a second emitting layer, a third emitting layer, a receiving layer, an electron buffering layer and a negative electrode from bottom to top. From the first emitting layer to the third emitting layer, the LUMO energy levels and the HOMO energy levels of materials are sequentially increased or are not reduced, the energy gaps are sequentially reduced, and the difference between every two adjacent LUMO energy levels is smaller than 0.4 eV. Transmission of excitons is improved in the mode that excitons of the third layer are blocked through the first layer and the second layer, and the hole mobility of the second layer is optimized. Spectra of multiple materials are overlaid, and therefore the absorption efficiency is improved. The organic thin-film solar cell is beneficial for increasing the FF, the light current and the short-circuit voltage of the solar cell, and finally the photoelectric converting efficiency is improved.