Fabrication and Optoelectronic properties of Fluoride tin oxides/porous silicon/p-Silicon heterojunction

In this paper, formation of a nanostructure semi transparence fluoride tin oxides (FTO) by spray pyrolysis technique on porous silicon PS layer. Porous silicon PS layer was prepared by anodization of p-type silicon wafers to fabricate of the UV- Visible Fluoride-doped tin oxide /Porous silicon /p-Si heterojunction photodetector. Optical properties of FTO thin films were measured. The optical band gap of 3.77 eV for SnO₂ : F for film was deduced. From (I-V) and (C-V) measurements, the barrier Ø_B height for FTO/PS diode was of 0.77, and the built in voltage V_bi, which was of 0.95 V. External quantum efficiency was 55 % at 500 nm which corresponding to peak responsivity of 1.15 A/W at 1 V bias. The PS band gap in the vicinity of PS/c-Si heterojunction was 1.38 eV.