Express characterization of indirect semiconductor surfaces by in situ photoluminescence during chemical and electrochemical treatments

The interband photoluminescence (PL) of indirect semiconductors is controlled by the non-radiative bulk and surface recombination processes and in this way the PL signal is a measure for surface passivation. We demonstrate a stroboscopic PL probe as a powerful tool for the express in situ control of indirect semiconductor surfaces during low temperature passivation processes. Samples of Group IV and III–V indirect-gap semiconductors (c-Si, c-Ge, c-SiGe and epitaxial layers and c-GaP) are investigated during chemical and electrochemical treatments. The surface passivation of Si and Ge depends differently on the pH.