The study of dependency of external quantum efficiency of triple-junction solar cells on measurement condition

We investigated the measurement technique for the external quantum efficiency (EQE) in triple-junction solar cell. We focused the bias voltage dependence of the EQE signal and the intensity of the incident light to the upper layer. The voltage dependence exhibited several patterns with the quantity of the leak current of the Ge-bottom cell. On the irradiated cells by the low energy proton, the bottom EQE was affected since the quantity of the photocurrent. In addition we tried to introduce the LED bias light method to estimate the effect of the photoluminescence.