Study on PbS Thin Films Fabricated by Screen Printing Method

PbS precursor powders were prepared by an organic molten salt method and the PbS precursor powders are dispersed in terpineol to prepare screen printing paste. The PbS paste is deposited on ordinary glass substrate by the screen printing method to form the PbS absorber layer and the printed PbS absorber layers are annealed and characterized by XRD, SEM, ultraviolet-visible (UV-vis) and photoluminescence (PL) spectra, respectively. XRD results indicated that the prepared sample is only PbS phase. SEM results indicated that the PbS thin films are composed by loose, uniform distribution, nanorod-like PbS nanocrystals with the diameter of about 100 nm and the length of about 2~5μm. Through study on the screen printing process, the results showed that with the increase of the number of screen printing, PbS film thickness increases gradually, when the number of screen printing is 3 times, the film thickness is 2μm. The UV-vis and PL spectra results indicated that the PbS thin films exhibited a large absorbance property in the wavelength range of 350~1100 nm and the PL spectrum had a broad emission band centered at 488 nm. The nanorod-like PbS thin films might have potential application in solar cells.