Cylindrical lens array concentrator with a nanonipple-array antireflective surface for improving the performances of solar cells

Nanoscale nipple array (NNA) structures have always been used in solar cells for the purpose of antireflection. However, most NNAs are fabricated on the planar surface of a film. Here, we report NNA structures are fabricated on the curved surface of a millimeter-scale cylindrical lens array concentrator (MCLAC) using the simple soft imprint method. The MCLAC concentrates all incoming sunlight to silicon surface of solar cells to overcome the reflection loss from finger electrodes. The NNAs on the surface of MCLAC can reduce the reflection loss at the lens–air interface and enhance the hydrophobicity of solar cell. Through applying the polymer multiscale AR coating consisting of NNAs and MCLAC(NNA–MCLAC) to commercial polycrystallinesilicon solar cells and optimizing the supporting layer height between MCLAC and silicon film, the power conversion efficiency (PCE) has been successfully improved from 18.60% to 19.52% under normal incidence, increased by 4.95%. Importantly, compared with the solar cell with the no structure planar coating, the relative PCE improvement ratio of the solar cell with the multiscale NNA–MCLACAR coating increases from ca. 5% up to ca. 32% when the incident angle increases from 0°to 60°. These remarkable improvements are of significance for practical deployment of commercial solar cells panels without a costly solar tracking system.