AC Back Surface Recombination Velocity in n<sup>＋</sup>-p-p<sup>＋</sup> Silicon Solar Cell under Monochromatic Light and Temperature

Abstract

Excess minority carrier's diffusion equation in the base of monofaciale silicon solar cell under frequency modulation of monochromatic illumination is resolved. Using conditions at the base limits involving recombination velocities Sf and Sb, respectively at the junction (n + /p) and back surface (p + /p), the AC expression of the excess minority carriers' density δ (T, ω) is determined. The AC density of photocurrent J ph (T, ω) is represented versus recombination velocity at the junction for different values of the temperature. The expression of the AC back surface recombination velocity Sb of minority carriers is deduced depending on the frequency of modulation, temperature, the electronic parameters (D (ω)) and the thickness of the base. Bode and Nyquist diagrams are used to analyze it.

Optimization of the thickness of the doping rate base (Nb) of the (n+/p/p+) silicon solar cell with vertical multi-junctions connected in series and placed under monochromatic illumination in frequency modulation

“…Sb: is the recombination rate [30][31][32][33] of the minority charge carriers at the rear face of the base.…”

“…At high speeds (Sf) of the recombination of minority charge carriers at the junction (short-circuit condition of the solar cell), the photocurrent density is constant. This constant value corresponds to the density of the shortcircuit current, and this makes it possible to establish the following equation [19,21,28,30,31]: .…”

Optimisation de l’épaisseur de la base de taux de dopage (Nb) de la photopile (n+/p/p+) au silicium à multi jonctions verticales connectées en série et placée sous éclairement monochromatique en modulation de frequence

“…Sb : est la vitesse de recombinaison [30,31,32,33] des porteurs minoritaires de charge à la face arrière de la base.…”

“…Aux grandes vitesses (Sf) de la recombinaison des porteurs minoritaires de charge à la jonction (condition de court-circuit de la photopile), la densité de photocourant est constante. Cette valeur constante correspond à la densité du courant de court-circuit, et ceci permet d'établir l'équation [19,21,28,30,31] suivante: . tanh ( 𝐻 𝐿(𝜔,𝑁 𝑏 ) )…”

Diffusion Coefficient at Double Resonances in Frequency and Temperature, Applied to (n<sup>+</sup>/p/p<sup>+</sup>) Silicon Solar Cell Base Thickness Optimization under Long Wavelength Illumination

“…[16] [26][35] [36] [44][49] [50][51]. They are function of, maximum diffusion coefficient D(ω c , T opt ), absorption coefficient of monochromatic illumination (α(λ)) and thickness (H) of the base.…”