Datasets associated with the Publication "Role of Nanoscale Compositional Inhomogeneities in Limiting The Open Circuit Voltage in Cu(In,Ga)S2 Solar Cells" . All data was acquired in an Attolight Allalin 4027 Chronos dedicated CL-SEM with a 150 l/mm and 500 nm blazed grating. All measurements were taken at room temperature with an electron beam acceleration voltage of 6.0 kV and a current of 3.0 nA with 90% of the beam energy being deposited within a depth of ~ 150 nm according to Monte Carlo CASINO simulations. Initial CL images were observed to suffer from significant drift due to charging, so the samples were carbon-coated to improve the conduction of the beam electrons away from the surface. All data treatment was performed using the Python hyperspy library.