Q2. What is the spectra of the two zones?
The spectra of both zones exhibit a shoulder at 255 cm-1, which is believed to be the convolution of peaks corresponding to Sn2S3, CZTS, Cu2-xS and ZnS [11-15].
Q3. What is the important fact about the Raman analysis?
Since there is almost no cubic ZnS Raman peak and the only published data of Raman is for monograins not for thin films the authors have associated the 338cm-1 peak to CZTS [15].
Q4. How are the two steps used to grow CZTS?
Non vacuum methods have also been developed, namely sulfurization of sol-gel deposited precursors by K. Tanaka et al. and spray-pyrolysis by N. Nakayama et al. and N. Kamoun et al. [7 - 9].
Q5. What is the process of forming the CZTS layer?
The sample preparation process begins with the substrate cleaning, a 9 cm2 SLG, withsuccessive ultrasound baths of acetone/alcohol/deionised water.
Q6. What was the evaporation temperature of the CZTS?
The SEM/EDS systemsused were a SEM Hitachi S4100 and a Rontec EDS with setting parameters of 25 KeV and 10 µA forsurface imaging and a Hitachi SU-70 with a Quantax Bruker AXS EDS system with 15/25 KeV and 40µA for cross-section imaging.
Q7. What was the average concentration ratio of Sn in the samples?
The EDS analysis showed that all samples had an excess of Sn and an average concentration ratio of 0.87 and 0.40 for [Cu]/([Zn]+[Sn]) and [Zn]/[Sn], respectively.
Q8. What is the XRD analysis of S330?
In both samples, XRD analysis detected elemental Zn. For S425 the Raman scattering analysis shows major peaks, at 264 cm-1, 304 cm-1 and 356 cm-1 corresponding to Cu2-xS [12], Sn2S3 [11] and cubic ZnS [13], respectively.
Q9. What is the purpose of the study?
Further research must be carried out to optimize the film quality, to produce a more compact layer and to improve the adhesion of the absorber layer to the back-contact.
Q10. What is the composition of the CZTS layer?
It can be observed a void or cavity between the CZTS and the Mo layer whichcould be created either during the film growth or during the cutting process.
Q11. How can the elimination of Cu2SnSnS be performed?
The elimination of Cu2-xS phases may be performed using a more accurate composition control of the metallic precursors and/or a chemical surface treatment with KCN.
Q12. What are the disadvantages of the expensive materials?
Despite that, these still use rare and expensive materials like In, Ga and Te, they also use toxic elements like Cd and Se, which represent a disadvantage.
Q13. What is the process of deposition of the precursors?
The deposition conditions followed the recipe developed by J. Scofield et al. to ensure both low resistivity and good adhesion to the SLG [10].