Frequency-Division-Multiplex-Based Quantum Efficiency Determination of Solar Cells

Quantum efficiency (QE) is an important measurand that 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 this paper, a new real-time characterization method is presented, which allows accelerating QE 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.