Internal quantum effeciency measurements of GaInP quantum well laser material using liquid contact luminescence

A liquid contact luminescence (LCL) technique is described. LCL spectral data obtained by current injection through two GaInP quantum well laser wafers are utilized to determine the internal quantum efficiency ratio for the two wafers. This measured ratio is shown to be in good agreement with the internal quantum efficiency ratio for the two wafers as determined from conventional laser slope efficiency vs. cavity length measurements.