We describe stacked photovoltaic modules, and components thereof, in which at least one booster cell is combined with at least one primary cell in a stacked configuration. The booster cell may be in the form of a polycrystalline film disposed on a transparent substrate, such as a glass substrate, and the film may be patterned to form multiple booster cells. The booster cell includes an n-type layer and a p-type layer; the n-type layer may include polycrystalline zinc sulfide (ZnS), and the p-type layer may include polycrystalline zinc telluride (ZnTe). The n-type layer may have a band gap energy of at least 3.5 eV, and the p-type layer may have a band gap energy of at least 2 or at least 2.2 eV, or in a range from 2.2 to 2.3 eV. An intrinsic layer, also comprising polycrystalline ZnTe, may reside between the n-type and p-type layers.