A bifacial silicon solar cell under monochromatic illumination in frequency modulation by the rear side is being studied for the optimization of base thickness. The density of photogenerated carriers in the base is ob...A bifacial silicon solar cell under monochromatic illumination in frequency modulation by the rear side is being studied for the optimization of base thickness. The density of photogenerated carriers in the base is obtained by resolution of the continuity equation, with the help of boundary conditions at the junction surface (n<sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">/p) and the rear face (p/p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">) of the base. For a short wavelength corresponding to a high absorption coefficient, the AC photocurrent density is calculated and represented according to the excess minority carrier’s recombination velocity at the junction, for different modulation frequency values. The expression of the AC recombination velocity of excess minority carriers at the rear surface of the base of the solar cell is then deduced, depending on both, the absorption coefficient of the silicon material and the thickness of the base. Compared to the intrinsic AC recombination velocity, the optimal thickness is extracted and modeled in a mathematical relationship, as a decreasing function of </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">modulated frequency of back illumination. Thus under these operating conditions</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> a maximum short-circuit photocurrent is obtained and a low</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">cost bifacial solar cell can be achieved by reducing material (Si) to elaborate the base thickness.</span>展开更多
文摘A bifacial silicon solar cell under monochromatic illumination in frequency modulation by the rear side is being studied for the optimization of base thickness. The density of photogenerated carriers in the base is obtained by resolution of the continuity equation, with the help of boundary conditions at the junction surface (n<sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">/p) and the rear face (p/p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">) of the base. For a short wavelength corresponding to a high absorption coefficient, the AC photocurrent density is calculated and represented according to the excess minority carrier’s recombination velocity at the junction, for different modulation frequency values. The expression of the AC recombination velocity of excess minority carriers at the rear surface of the base of the solar cell is then deduced, depending on both, the absorption coefficient of the silicon material and the thickness of the base. Compared to the intrinsic AC recombination velocity, the optimal thickness is extracted and modeled in a mathematical relationship, as a decreasing function of </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">modulated frequency of back illumination. Thus under these operating conditions</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> a maximum short-circuit photocurrent is obtained and a low</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">cost bifacial solar cell can be achieved by reducing material (Si) to elaborate the base thickness.</span>
