Lock-in carrierography non-destructive imaging of silicon wafers and silicon solar cells

Carrier transport and electrical properties are relevant to the performance of semiconductor materials and photovoltaic devices. In recent years, various kinds of high-resolution luminescence-based methods have been proposed to image these properties. Lock-in carrierography (LIC), as a dynamic photoluminescence-based method, has the advantages of self-calibration, higher signal to noise ratio than dc or transient modalities, and high-frequency imaging ability. At the present stage of development, LIC has evolved into homodyne lock-in carrierography and heterodyne lock-in carrierography. In this Perspective, we discuss the principles and theoretical background of both LIC modalities and review experimental systems and methods. In addition, we also provide a brief overview of key LIC applications and future outlook.