Hairlike carbon-fiber-based solar cell

This paper reports the fabrication and photovoltaic (PV) demonstration of macro-length, micron-diameter hairlike solar cells. In this design of cylindrical silicon solar cell with a radial p-n architecture, the carbon fiber (CF) serves as the core electrode as well as fabrication substrate, and polysilicon (poly-Si) is used as the shell photoactive material. Uniform deposition of poly-Si on the cylindrical-shape CF substrate was achieved by low pressure chemical vapor deposition (LPCVD) with the silicon layer thickness ranging from 0.85 um to 10 um. A preliminary study of an 11 um-diameter single-fiber solar cell demonstrates that this initial device exhibits photovoltaic effect with an open-circuit voltage (V_oc) of 0.14 V, a short-circuit current density (J_sc) of 1.7 mA/cm² and an efficiency of 0.04%.