Time-resolved PL measurements in the growth of high voltage (Al)GaInP/GaAs solar cells

Aluminum doped GaInP, (Al)GaInP hereafter, is used as absorber in double-junction (Al)GaInP/GaAs solar cells, to enhance the open-circuit voltage and further the efficiency. By investigating the time-resolved PL of (Al)GaInP/AlGaInP heterojunction, whose interface is equivalent to that of base/backsurface-field (bsf), the bulk lifetime and interface recombination velocity are obtained. With further improvements, a recombination velocity of 139 cm/s is achieved at the interface between the base and bsf. A preliminary double-junction solar cell is grown and fabricated, showing an open-circuit voltage (Voc) of 2506 mV and a short-circuit current (Jsc) of 15.6 mA/cm
²
only. With further current matching, including thickening the base, employing transparent tunnel diode and improving the anti-reflection coating, this solar cell could be used as top-cell in Ge-based solar cell, IMM solar cells and SBT solar cells, to approach higher conversion efficiency.