Effect of bulk Defect Concentration on Capacitance Characteristics of an Experimentally Calibrated CIGS Solar Cell Using SCAPS-1D via Admittance Spectroscopy

Ahmed K. Marei; Ayed N. Saleh

doi:10.51699/cajmns.v7i4.3342

Authors

Ahmed K. Marei Department of Physics, College of Education for Pure Science, University of Tikrit, Iraq
Ayed N. Saleh Department of Physics, College of Education for Pure Science, University of Tikrit, Iraq

DOI:

https://doi.org/10.51699/cajmns.v7i4.3342

Keywords:

CIGS Solar Cells, SCAPS-1D, Admittance Spectroscopy, Bulk Defects, Activation Energy

Abstract

In this work, the combined effect of temperature (184–304 K) and defect concentration (1.4 × 10¹²–1.4 × 10¹⁶ cm⁻³) on the capacitance characteristics of a calibrated Cu(In,Ga)Se₂ (CIGS) solar cell was systematically investigated using Solar Cell Capacitance Simulator in one dimension (SCAPS-1D) via admittance spectroscopy. The results show that the characteristic frequency shifts significantly with temperature from approximately (~3.7×102 Hz) at (184 K) to (~5.1× 106 Hz) at (304 K), indicating a thermally activated emission process spanning nearly three orders of magnitude. Meanwhile, increasing defect concentration reduces the low-frequency capacitance from (~65.7 nF/cm²) to (~61.4 nF/cm²) and enhances the visibility of the defect response without altering its intrinsic energy level. The derivative analysis (−ƒ×dC/dƒ) enabled precise extraction of the characteristic frequencies, especially at high defect concentration (1.4 × 10¹⁶ cm⁻³), where sharp and well-defined peaks were observed. The Arrhenius analysis yielded an activation energy of (0.328 eV), which is lower than the introduced defect level (0.88 eV), reflecting the effective emission barrier relative to the conduction band. These findings confirm that temperature controls the dynamic defect response, while defect concentration primarily governs the amplitude and detectability, providing a reliable framework for defect characterization and optimization of CIGS solar cells.

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