Methods for simultaneously making quantum efficiency measurements at multiple points in a photovoltaic cell are provided. A light beam (e.g., monochromatic light) can be directed to a first beam splitter, where it is split into a first reflected portion and a first passthrough portion such that the first reflected portion is directed to a first point on the photovoltaic cell. The first reflected portion can then be chopped at a first frequency between the first beam splitter and the first point. The first passthrough portion of the light beam can be reflected at a second beam splitter to a second point on the photovoltaic cell. The second reflected portion can then be chopped at a second frequency between the second beam splitter and the second point. Finally, the quantum efficiency can be calculated at both the first point and the second point. Systems are also generally provided for simultaneously making quantum efficiency measurements at multiple points in a photovoltaic cell.