Analysis of GaInP Solar Cells Grown by Hydride Vapor Phase Epitaxy

We analyzed the performance of a simple n-on-p GaInP solar cell grown without surface passivation but with a back reflector by dynamic hydride vapor phase epitaxy (DHYPE). We employed a thin emitter because the lack of surface passivation limited collection in that layer. We obtained a maximum internal quantum efficiency of nearly 95% by using 1 x 10^16 cm^-3 base doping. This device exhibited an open circuit voltage (VOC) of 1.27 V, short circuit current (JSC) of 12.6 mA/cm^2 , a fill factor (FF) of 79.3%, and 12.8% efficiency. Limits on cell performance predominantly come from VOC and FF. A Suns-VOC analysis of this cell indicates that 5.5% (absolute) of the FF is lost to series resistance, which stems from a high contact resistance. Another 5.5% of FF loss results from elevated dark current, leading to non-ideal diode behavior. This behavior implies that improvement in bulk material quality through reduction in concentrations of non-radiative defects will improve cell performance.