Minimizing the Cycle Time for a Rapid Quantum Efficiency Measurement by Modulating Multiple Channels of LED Solar Simulators

Abstract

LED-based solar simulators have been shown to provide many advantages compared to Xenon-based flashers in particular regarding the flexibility of the spectrum, flash duration and illumination intensity. Using these extended capabilities, several new inline measurement applications, such as a rapid quantum efficiency (rapid-EQE) or rapid reflectivity measurement have been developed in recent years. In our work, we demonstrate how the rapid-EQE method can be further accelerated by using modulated LED light sources where the data acquisition for the various wavelengths occurs simultaneously during one measurement step. Our results show that the modulated rapid-EQE yields equivalent results compared to the consecutive measurements employed in previous rapid-EQE approaches. Thus, the accelerated approach can be integrated into inline LED solar simulators even for the strongly decreasing cycle times in modern production lines.