Mixture, functional layer, photoelectric conversion element and perovskite stabilizer

Provided are the following: a mixture containing a quinone-based compound such as benzoquinone and a perovskite type compound such as a lead iodide type compound; and a photoelectric conversion element having a layer that contains a quinone-based compound and a perovskite type compound. This element is configured so that the generation of metals from the perovskite type compound and deterioration over time of element characteristics are suppressed, the element has a long life, and stable operation even in high humidity environments is possible.