Extending the Single‐Diode Model With Spectral Sensitivity for Different PV Materials Under Varying Solar Spectra

ABSTRACT Due to environmental dynamic variability, spectral fluctuations arise in the incident photon flux, leading solar cells to operate under diverse spectral regimes with distinct carrier generation characteristics. As the conventional single‐diode model (SDM) neglects spectral dependency, this study extends the SDM of the PV cell with spectral sensitivity by incorporating wavelength‐dependent photogenerated current. Three semiconductor materials, including Si, GaAs, and Ge, are investigated under both ideal and realistic operating conditions, using an SDM‐based representation implemented in MATLAB/Simulink under AM0 and AM1.5G solar spectra. The findings demonstrate how different spectral behaviors influence the output characteristics of each solar cell, even when their theoretical Shockley–Queisser limits are nearly identical. Accordingly, a new analytical metric of wavelength‐based efficiency is introduced, providing a deeper understanding beyond standard efficiency calculations. This metric enables the evaluation of the overall efficiency under varying solar spectra. The proposed concept provides valuable insights into how semiconductor materials and spectral responses influence solar cell efficiency. Furthermore, it offers practical guidance for optimizing solar cell designs and selecting materials for specific applications.