Properties of Black Silicon Layers Fabricated by Different Techniques for Solar Cell Applications

Black silicon (BS) layers coated with passivation films are widely used as antireflective frontal surfaces for solar cells. The most common BS fabrication techniques are reactive ion etching (RIE), metal‐assisted chemical etching, and laser‐induced processing. Herein, the structural and optical properties, as well as the minority carrier lifetime, of BS are compared with and without atomic layer deposited HfO2 passivation films produced by the above formation methods. The antireflection behavior of the samples is discussed based on the light trapping effect and the change in the BS refractive index from air to the bulk of crystalline Si. Finally, test solar cells are manufactured, and their photovoltaic parameters are studied. The comparison results show that RIE is the most preferred in all technical respects. The features of using different BS fabrication techniques from the solar cell manufacturing point of view are analyzed. The structural and optical properties, as well as the minority carrier lifetime, of black silicon with and without atomic deposited layered HfO2 passivation films fabricated by reactive ion etching, metal‐assisted chemical etching, and laser‐induced processing techniques are compared.