At room temperature, the bias dependence of a far-infrared electroluminescence image of a photodiode is investi-gated in the dark condition. The results show that the electroluminescence image can be used to detect defects in the photodiode. Additionally, it is found that the electroluminescence intensity has a power law dependence on the dc bias current. The photodiode ideality factor could be obtained by a fitting a relationship between the electroluminescence intensity and the bias current. The device defect levels will be easily determined according to the infrared image and the extracted ideality factor value. This work is of guiding significance for current solar cell testing and research.
The far-infrared electroluminescence characteristics of an InGaP/InGaAs/Ge solar cell are investigated under forward DC bias at room temperature in dark conditions.An electroluminescence viewgraph shows the clear device structures,and the electroluminescence intensity is shown to increases exponentially with bias voltage and linearly with bias current.The results can be interpreted using an equivalent circuit of a single ideal diode model for triple-junction solar cells.The good fit between the measured and calculated data proves the above conclusions. This work is of guiding significance for current solar cell testing and research.
