Spray deposition and characterization of nanostructured Li doped NiO thin films for application in dye-sensitized solar cells

Abstract

Transparent conducting Li (0-5 wt%) doped NiO thin films with preferential growth along the (111) plane were deposited onto glass substrates by pyrolytic decomposition of nickel nitrate and lithium chloride precursors at 500 °C in air. The effect of Li concentration on the structural, optical and transport properties of NiO thin films was studied by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectral transmittance, photoluminescence and linear four-probe resistivity. Activation energies as a function of Li concentration were deduced from the temperature dependent resistivity data measured in the range 300-448 K. The figure of merit was deduced by combining the spectral transmittance and sheet resistance values. The variation in properties of NiO thin film due to Li doping are discussed based on the above results. A dye-sensitized solar cell has also been fabricated for the optimized Li doped NiO thin film and the results are presented.

Giant dielectric permittivity in Li and Pr co-doped NiO ceramics

“…The NiO grains grow in size due to the Li doping (sample NiO:Li) that improve the crystallinity of the sample, as also observed in Ref. [19]. The grain growth continued with addition of Pr as in LPNO-1, and then followed by decreasing with more addition of Pr as in sample LPNO-2.…”

“…Creation of Ni 2+ vacancies disturb its lattice locally and transform it into p-type semiconductor [1]. p-Type semiconducting behaviour of NiO can be boosted by doping with monovalent cations such as Li + , similar to that of an acceptor impurity function [19]. However, the conductivity of a pressed reference NiO disc in the present work is 4.23 × 10 −7 S/cm, which is close to the range (10 −1 to 10 −6 S/cm) usually found experimentally by many researchers [19].…”

“…p-Type semiconducting behaviour of NiO can be boosted by doping with monovalent cations such as Li + , similar to that of an acceptor impurity function [19]. However, the conductivity of a pressed reference NiO disc in the present work is 4.23 × 10 −7 S/cm, which is close to the range (10 −1 to 10 −6 S/cm) usually found experimentally by many researchers [19]. This means that the calcination of the reference NiO creates structural Ni 2+ vacancies that improve the conductivity.…”

“…Thus with a little Li doping (Li 0.027 Ni 0.973 O), a considerable increase in its conductivity takes place, in agreement with the results of Refs. [1,18,19] obtained from NiO:Li thin film. The dc-conductivity of LPNO-1 was 3.34 × 10 −6 S/cm and of LPNO-2 was 9.1 × 10 −4 S/cm.…”

Spray-on Thin Film PV Solar Cells: Advances, Potentials and Challenges

“…Also, Nb 2 O 5 produced by spray pyrolysis may be used as the counter electrode in a DSSC [52]. Transparent conducting Li-doped NiO thin films [53] and water-soluble polyelectrolyte-grafted multi-walled carbon nanotube films [54] are the other layers that may be fabricated by spray pyrolysis.…”