Application Of Silicon-based Micro-pencil Array Structure In Solar Cells

Black silicon with nanotextures has excellent light trapping effect without additional antireflection layer.However,it is limited by serious recombination and large parasitic area in practical applications,which will abate part of the values of black silicon since passively adopting shallow textures and relying on additional antireflection and high quality passivation layer.In this disseration,we have adopted a micron-sized array structure instead of the traditional nano-sized texture to solar cells.The micro-array structure is capable of controlling the average reflectance below 2%and has good light absorption performance.We show that silicon microwire solar cells featuring well-defined radial junctions can extensively suppress both surface and Auger recombination by providing excellent all-around electrical field.The radially doped silicon micropillar devices even show an internal quantum efficiency as good as that of planar substrate and their measured minority carrier lifetimes become nearly independent of total surface area.A great reduction in short-circuit current density loss has further been identified as the junction abruptly changed from a fully diffused to a core-shell configuration,manifesting the powerful effectiveness of radial p-n~+junction on the suppression of Auger recombination.Furthermore,silicon microwire solar cell with a radial junction demonstrates 37%increase in efficiency compared with the reference cell,suggesting a bright future.