The quantum efficiency (QE) is an important measurand which contains extensive information about the electrical and optical properties of photovoltaic devices. During device characterization the measurement is, therefore, mandatory and necessary for e.g. spectral mismatch correction of subsequent examinations. In the present paper, a new real time characterization method is presented which allows accelerating quantum efficiency measurements by a factor of more than 500 times without significantly degrading measurement accuracy, optical bandwidth and resolution. The increased measurement speed is achieved by a frequency division multiplexing approach using a spatial light modulating element which allows it to illuminate the cell under test simultaneously with all wavelengths of interest. Feasibility and reproducibility are demonstrated in experimental measurements and validated by comparison with Fraunhofer ISE CalLab instruments.