Impact of doping on the physical properties of PbSe chalcogenide material for photovoltaic application

In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead selenide films. Using electrochemical deposition, we successfully deposited zirconium-doped lead selenide and undoped lead selenide films on FTO substrates. The X-ray diffraction pattern for the synthesized undoped and doped PbSe films shows a significant peak at the diffraction planes (220), (112), (310), (202), and (212) which confirm to the cubic structure with a preference orientation of the crystallites along the (202) plane. The Zr incorporation in the PbSe matrix opens up additional nucleation sites, inhibiting the formation of crystal grains and elevating the lattice strain, which may be the reason for the lower crystallinity in the PbSe/Zr films. With a thickness of 105.55nm, the undoped PbSe films were found to have resistivity and conductivity values of 6.20 x 10-5 (Ω.m) and 1.61 x 10-6 (S/m), respectively. When the Zr-dopant content was increased by 0.1 mol%, it was observed that the resistivity value climbed to 7.79 x 10-5 (Ω.m) and subsequently steadily decreased within the same range. The shrinkage of the PbSe/Zr films' grain size is responsible for the modest rise in resistivity. With a rise in Zr-dopant, the electrical conductivity falls from 1.61 x 10-6 (S/m) to 1.29 x 10-6 (S/m). An increase in the resistivity caused a drop in the conductivity. The bandgap for undoped PbSe is 1.10 eV. The bandgap was raised to 1.40–1.70 eV after adding Zr-dopant at a 0.1-04 mol% concentration.