The external quantum efficiency (external QE or EQE) of a solar cell is the percentage of photons striking the cell that are converted into electrical current. The EQE is a measure of the efficiency of a solar cell at converting sunlight into electrical energy.The EQE can be measured by shining light on the solar cell and measuring the current that is generated. The EQE can also be calculated from the internal quantum efficiency (IQE) and the reflectance of the solar cell.
