Abstract
In this work, Cu2ZnSnS4 (CZTS) precursor films were deposited using a water-based solution approach. Subsequently, selenization was performed at different temperatures in the range of 480–610 °C to prepare Cu2ZnSn(S,Se)4 (CZTSSe) absorber-layer films. The effects of the selenization temperature on the crystallinity, structure, morphology, and photoelectric properties of CZTSSe thin films, as well as the performance of solar cells constructed using these films, were systematically studied. The absorber-layer films selenized at different temperatures all formed pure-phase CZTSSe and had basically the same film thickness. It was found that application of an optimal selenization temperature can enhance the crystallinity, crystal grain size, and mobility and reduce the resistivity of CZTSSe films. Selenization at 550 °C resulted in the largest grain size (∼μm), the highest crystallinity, the highest mobility (4.29 cm2 V−1 s−1), the lowest resistivity (3.13 × 102 Ω cm), the thinner fine-grained layer, a bandgap value of 1.21 eV, and a Cu-poor, Zn-rich elemental composition [Cu/(Zn + Sn) = 0.85 and Zn/Sn = 1.16]. The power-conversion efficiency was improved from 3.04% in a CZTSSe cell device with an absorber layer selenized at 480 °C to 4.69% in a film selenized at 550 °C. This was mainly due to the improvement of the crystallinity, crystal grain growth, and reduction of the fine-grained layer of the CZTSSe film. These results show that optimizing the selenization temperature is essential for enhancing the performance and the ultimate device efficiency of CZTSSe absorber layers prepared using a water-based solution approach.
Highlights
The last several decades have seen remarkable development of Cu(In,Ga)Se2 (CIGS) solar cells, achieving a 22.6% powerconversion efficiency (PCE).1 the rarity and high cost of In and Ga have increased the need for alternative materials
The broad and weak diffraction peaks indicate that the CZTS crystal grains were small; the average grain size of the CZTS precursor film estimated via the Debye–Scherrer formula was about 18 nm
When selenized at 550 ○C, the (112) peaks were clearly intensified compared to selenization at a temperature of 480 ○C, and this was accompanied by a reduction in the full width at half maximum, indicating larger crystal grains and higher crystallinity
Summary
The last several decades have seen remarkable development of Cu(In,Ga)Se2 (CIGS) solar cells, achieving a 22.6% powerconversion efficiency (PCE). the rarity and high cost of In and Ga have increased the need for alternative materials. There is an urgent need to find an environmentally friendly and less toxic solvent to replace hydrazine in the process of preparing CZTSSe solar cells. Ethanol and 1butylamine, CS2 and thioglycolic acid, ethanolamine and thioglycolic acid, thioglycolic acid and methylamine, ethanedithiol and ethylenediamine,12 2-methoxyethanol, and other solvents have shown good performance in the preparation of CZTSSe solar cells. Water-based solution approaches for preparing CZTSSe solar cells have drawn considerable attention. Tian et al fabricated a CZTSSe cell having a record 6.62% efficiency, confirming the potential of water-based solution approaches for producing highly efficient CZTSSe solar cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
