Impedance spectroscopy of monocrystalline silicon solar cells for photosensor applications: Highly sensitive device

In this study, the AC impedance measurements have been used to characterize the monocrystalline silicon solar cell device under dark and illumination conditions. AC impedance measurements in the illuminated conditions are analyzed to identify the electronic behavior through equivalent AC circuit representation in terms of lumped parameters obtained by fitting the measured impedance data. The angle impedance phase increases from negative to positive values with increasing illumination conditions. The real part Z′ of the complex impedance value is typically higher at the dark light in the low-frequency region. It decreases gradually with increasing frequency reaching a plateau demonstrating independence on illumination at high frequencies. Nyquist plots exhibited a semicircle associated with the bulk single-crystalline body, and an additional spike is distinguishable at high frequency. The AC electrical conductivity is changed under dark and illumination conditions. Finally, the studied solar cell shows a highly sensitive light impedance response suggesting its suitability for use in photosensor applications.