Filterless Spectral Splitting Perovskite-Silicon Tandem System with >23% Calculated Efficiency

We demonstrate an efficient spectrum splitting perovskite-silicon tandem in which the perovskite cell absorbs short wavelength light to generate photocurrent and selectively reflects long wavelength light to the silicon cell. The concept eliminates the need for the sophisticated optical splitter in other spectrum splitting approaches, which could reduce the cost of the system. Using this approach, we demonstrate a calculated four-terminal tandem efficiency of 23.1% measured under AM1.5G simulated sunlight, using a silicon cell with a one Sun efficiency of 22.4%. The result has been obtained through the optimization of the perovskite cell to achieve an outstanding subbandgap wavelength reflection of >90% and excellent angular response of the perovskite cell, even with no AR coating.