Time-resolved correlative optical microscopy of charge-carrier transport, recombination, and space-charge fields in CdTe heterostructures
From time- and spatially resolved optical measurements, we show that extended defects can have a large effect on the charge-carrier recombination in II-VI semiconductors. In CdTe double heterostructures grown by molecular beam epitaxy on the InSb (100)-orientation substrates, we characterized the extended defects and found that near stacking faults the space-charge field extends by 2-5 μm. Charge carriers drift (with the space-charge field strength of 730-1,360 V cm-1) and diffuse (with the mobility of 260 ± 30 cm2 V-1 s-1) toward the extended defects, where the minority-carrier lifetime is reduced from 560 ns to 0.25 ns. Furthermore, the extended defectsmore »