Silicon photoluminescence external quantum efficiency determined by combined thermal/photoluminescence measurements

A high photoluminescence external quantum efficiency (EQE) of 3.1% has been measured for a passivated, textured silicon wafer using a combined thermal and photoluminescence technique. This result shows that the high photoluminescence EQEs reported recently, which were achieved using calibrated photoluminescence measurements, are confirmed with an entirely independent measurement technique. The technique involves measuring uncalibrated photoluminescence and thermal signals from an optically pumped structure as a function of incident laser power. The ac measurement technique allows direct measurement of microkelvin temperature differences at room temperature, and also allows the recombination coefficients of the sample to be determined.