Study of 980 nm GaAs based pumping lasers by photo-voltage spectroscopy

Application of photo-voltage spectroscopy (PVS) technique in the study of semiconductor superlattices (SLs) and quantum well (QW) structures is presented. Room temperature (RT) PVS spectra in the vicinity of the active layers of the structures display several interesting features that originate from carrier quantum confinement. A sharp exciton absorption peak was obtained at RT. The other features namely, splitting between the heavy and light holes, other high quantum confinement levels have also been observed. The PVS measurements have been compared with that of photoluminescence (PL) measurements. The QW wavelengths by PVS measurements were always higher than that of PL measurements and it is due to quantum confined Stark effect (QCSE).