Structural, optical and electrical properties of Cu2FeSnX4 (X=S, Se) thin films prepared by chemical spray pyrolysis

Sulfur stoichiometry driven chalcopyrite and pyrite structure of spray pyrolyzed Cu-alloyed FeS2 thin films

“…The grain sizes of annealed films are enhanced with increasing Cu concentration (x) which is possibly due to the facilitation of Cu on grain growth [27]. The thicknesses of synthesized films were measured to be in the range of 1.3-2 mm which is similar to earlier reports [17,28,31].…”

“…It is to be noted that the precursor prepared with mixture of solvent is found to be more stable than that prepared with only de-ionized water and it also increases the growth rate of film during deposition. The precursor solutions were sprayed on soda lime glass (SLG) substrates at temperature of 450°C in ambient air using the homemade ultrasonic spray system with which high electrostatic field of 30 kV was applied between outlet of aerosol flow pipe and substrate base plate as previous report [28][29][30]. Nitrogen gas was used as carrier gas to flow mist of aqueous solution which was controlled by gas flow meter.…”

“…CSP is one of the simple and effective methods to fabricate thin film with controlled cation stoichiometry by adjusting the composition of respective chemical during preparation of spray precursor solution [27][28][29]. The synthesized films were characterized by field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and Hall effect measurement.…”

Structural and optical tunability by reaction time of selenization in Cu2FeSnSe4 thin films

“…Quaternary semiconductor CFTSe with high absorption coefficient (>10 -4 cm -1 ), suitable band gap, abundance of constituent and non-toxic elements make it attractive options as an alternative absorber material to CIGS [7]. A variety of techniques such as hot-injection method [8], aerosol assisted chemical vapour deposition method [9] and chemical spray pyrolysis method [10] etc. has been reported to fabricate CFTSe thin films.…”

“…The crystal structure of CFTSe is descendant from the CIS by the substitution of Fe, Sn for In, and we estimate that CFTSe may inherit the feature of CIS. However, previous studies mainly focused on the process synthesis of CFTSe material [7][8][9][10], hence, the technology for adjusting the structure, crystal orientation and optical properties of CFTSe are particularly important. For a typical two-stage process, the quality of thin films is strongly depends on the post-annealing process [15][16][17][18], so the authors set out to explore the tuning of the structure, crystal orientation and optical properties of CFTSe by changing the selenization process.…”