Characterization of quantum well structures using surface photovoltage spectroscopy

In this work a novel method to characterize quantum well (QW) structures an d devices is presented. The method is based on the well-known surface photo voltage spectroscopy (SPS) and on numerical simulations. It is shown that t he surface photovoltage is sensitive to the electron hole energy transition levels in the well layer as well as to features of other regions of the st ructure. The photovoltaic response as function of well width is numerically studied and is found to increase with decreasing well width. As a result o f the spectra analysis growth parameters such as quantum well width and ter nary layer composition (both of quantum well and cladding layers) are accur ately determined. In addition, structure properties such as electric fields and effective carriers lifetime at the well are estimated. Finally it is s hown that operating device parameters such the lasing wavelength may also b e obtained. The results demonstrate the power of SPS as a characterization method for QW structures and devices in a contactless and non-destructive m anner, (C) 2000 Elsevier Science S.A. All rights reserved.