Direct electrical contact of slanted ito film on axial p-n junction silicon nanowire solar cells

A novel scheme of direct electrical contact on vertically aligned silicon nanowire (SiNW) axial p-n junction is demonstrated by means of oblique-angle deposition of slanted indium-tin-oxide (ITO) film for photovoltaic applications. The slanted ITO film exhibits an acceptable resistivity of 1.07x10.3-cm underwent RTA treatment of T = 450C, and the doping concentration and carrier mobility by Hall measurement amount to 3.7x1020cm.3 and 15.8cm2/V-s, respectively, with an n-type doping polarity. Because of the shadowing effect provided by the SiNWs, the incident ITO vapor-flow is deposited preferentially on the top of SiNWs, which coalesces and eventually forms a nearly continuous film for the subsequent fabrication of grid electrode. Under AM 1.5G normal illumination, our axial p-n junction SiNW solar cell exhibits an open circuit voltage of VOC = 0.56V, and a short circuit current of JSC = 1.54 mA/cm2 with a fill factor of FF = 30%, resulting in a total power conversion efficiency of PEC = 0.26%.