Perovskite solar cells based on CH NH PbBr with a band gap of 2.3 eV are attracting intense research interests due to their high open-circuit voltage (V ) potential, which is specifically relevant for the use in tandem configuration or spectral splitting. Many efforts have been performed to optimize the V of CH NH PbBr solar cells; however, the limiting V (namely, radiative V :V ) and the corresponding ΔV (the difference between V and V ) mechanism are still unknown. Here, the average V of 1.50 V with the maximum value of 1.53 V at room temperature is achieved for a CH NH PbBr solar cell. External quantum efficiency measurements with electroluminescence spectroscopy determine the V of CH NH PbBr cells with 1.95 V and a ΔV of 0.45 V at 295 K. When the temperature declines from 295 to 200 K, the obtained V remains comparably stable in the vicinity of 1.5 V while the corresponding ΔV values show a more significant increase. Our findings suggest that the V of CH NH PbBr cells is primarily limited by the interface losses induced by the charge extraction layer rather than by bulk dominated recombination losses. These findings are important for developing strategies how to further enhance the V of CH NH PbBr -based solar cells.