Improved front contact of MoOx/n-type silicon heterojunction solar cells with high work function Zinc-doped Indium Oxide (IZO) layer

Transparent conductive coating (TCO) used as front contact layer in MoO
x
/n-Si heterojunction solar cells should feature excellent electrical properties, low optical absorption and high work function simultaneously. In this study, tin-doped indium oxide (ITO), titanium-doped indium oxide (ITiO) and zinc-doped indium oxide (IZO) deposited as front contact layer at room temperature by sputtering were evaluated. The open-circuit voltage is hardly affected by the work function of TCO film. The IZO front contact with Wf=5.22 eV enables to highest V
oc
of 606 mV. Meanwhile, high mobility and transmittance also boost the short-circuit current density to 33.04 mA/cm
²
. A cell efficiency of 12.2% has been achieved by applying IZO front contact and has high potential to obtain better electrical properties by introducing back surface field structure.