Improved performance mechanism of III–V compound triple-junction solar cell using hybrid electrode structure

To improve the conversion efficiency of InGaP/InGaAs/Ge compound triple-junction solar cells, the hybrid electrode structure consisting of the metal contact pads and the transparent indium–tin-oxide (ITO) film was designed. The metal contact pad was used to form good ohmic contact. The current extraction capability of the resulting solar cells was enhanced by reducing the interval of the metal contact pads. In addition, transparent ITO films were used to replace the conventional bus-bar metal electrodes to avoid shadow loss. To study the improvement mechanisms of the conversion efficiency, the designed electrodes with various intervals among the metal contact pads were fabricated on solar cells, and the performances were evaluated for comparison.

► The hybrid electrode composed of the metal contact pads and the ITO was designed.
► The metal contact pads of hybrid electrode were used to form good ohmic contact.
► The current extraction capability was enhanced by reducing the pad interval.
► The shadow loss of the hybrid electrode was less than 1%.