Two-dimensional device simulation and performance optimization of crystalline silicon selective-emitter solar cell

Abstract

In this paper, device simulation and parameter optimization on crystalline silicon (c-Si) selective-emitter (SE) solar cell are performed by using PC2D two-dimensional simulator. On the basis of achieving perfect fitting to the measured I-V curve of a typical c-Si SE solar cell fabricated by screen printing phosphoric paste method, the effects of physical parameters of gridlines, base, selective emitter and back surface field layer on the optoelectronic performance of the SE solar cell are comprehensively and systematically investigated. Simulation results show that the base minority carrier lifetime, the front surface recombination velocity and the back surface recombination velocity are the three largest efficiency-affecting parameters. In the studied parameter range, when the base minority carrier lifetime rises from 50 s to 600 s, the cell efficiency increaes from 18.53% to 19.27%. Low front surface recombination velocity is the premise of making the optimization of selective emitter sheet resistance meaningful. To obtain an ideal efficiency, the back surface recombination velocity should be controlled to be under 500 cm/s. In addition, under different front surface recombination velocities, the maximum of cell efficiency is always achieved in a range of 5090 / heavily doped region sheet resistance and 110180 / lightly doped region sheet resistance. For different numbers of gridlines, when the radio of heavily doped region width to the gridline pitch equals 32%, the solar cell has the highest efficiency. Moreover, under the condition of low area radio of bas bar, increasing bus bar number appropriately can improve the efficiency. The efficiency of p-type SE solar cell reaches 20.45% after optimization.