3D Modeling of a Polycrystalline Solar Cell under Guinean Climatic Conditions: Determination of Diffusion Length Using the Inverse of the External Quantum Yield as a Function of the Inverse of the Absorption Coefficient at Temperature

Abstract

A rise in temperature, respectively, leads to an increase in external quantum efficiency, giving broad spectral bands that shift to shorter wavelengths: from infrared to visible, then to ultraviolet. This effect is linked to the increased kinetic energy of the particles, leading to more intense collisions and greater absorption or emission of photons of different energies. EQE can increase in specific wavelength ranges, while the overall energy efficiency of the cell decreases. Spectral sensitivity increases sharply as temperature rises. This is due to a higher probability of creating electron-hole pairs. Photovoltaic cells work by absorbing light and generating electrons. A material’s ability to absorb light depends on its crystalline structure. In polycrystalline silicon, crystal boundaries can act as traps for charge carriers, reducing the number of electrons generated when the crystal size is small. Crystal boundaries are transition regions between different crystals, where the crystal pattern is distorted or disorganized. These defects act as capture zones for charge carriers, preventing the current from flowing efficiently. This can significantly reduce the efficiency of the solar cell. Very small crystal sizes and higher defect densities lead to a reduction in EQE, spectral sensitivity, and effective scattering length, particularly in spectral regions where light is normally well absorbed. Low effective scattering lengths are thus due to small crystal sizes and high temperatures. Polycrystalline solar cell manufacturers need to optimize crystal size to increase electricity production. Larger crystals (not too large) give better yields than smaller ones. In addition, Guinea, like all Sahelian countries, faces significant environmental challenges, including deforestation and air pollution. Aerosols, particularly from biomass combustion and agriculture, have a direct impact on air quality and can reduce the efficiency of solar panels by reducing solar irradiation. Increased aerosols in the atmosphere can reduce the efficiency of solar installations, a crucial aspect in optimizing energy projects. This study is part of the response to the lack of studies on the analysis of renewable energy potential in general, as well as solar energy in Guinea.