Heterojunction Perskovskite Photovoltaic Devices and Methods of Making the Same

An aspect of the present disclosures is a method that includes applying a perovskite precursor solution to a first solid conductor and treating the perovskite precursor solution such that a first portion of the perovskite precursor solution is converted to a first solid perovskite, where the first solid conductor comprises a first charge transport characteristic, which is predominantly p-type or predominantly n-type, and the treating results in the first solid perovskite having a second charge transport characteristic that is substantially the same as the first charge transport characteristic.