Fabrication and temperature-dependent performance of aluminum-alloyed back-junction n-type silicon solar cells

Aluminum-alloyed back-junction is a novel concept for low-cost and industrially feasible n-type silicon solar cells. In this paper, we fabricated industrially high-efficiency solar cells based on both uncompensated and compensated n-type silicon. Moreover, we measured the impact of temperature on the photovoltaic performance of aluminum-alloyed back-junction n-type silicon solar cells. Compared with conventional front-junction solar cells, the back-junction silicon solar cells have a lower absolute temperature coefficient especially for moderate carrier diffusion lengths which is attributed to distinctive spectral response, stronger dependence on carrier diffusion lengths, and incomplete ionization of aluminum. In addition, the lowest absolute temperature coefficient is obtained on this type of aluminum-alloyed back-junction solar cell when the compensated silicon is used as the base layer. These results suggest that aluminum-alloyed back-junction solar cells especially based on the compensated silicon can generate more electricity at a high temperature, and therefore, as a cost-effective production of silicon solar cells, this type of solar cells have a very good potential for actual outdoor application. This work is highly relevant to the development of an advanced process for the achievement of low-cost, high-efficiency, commercially viable silicon-based solar cells.