Kesterite (Cu2ZnSnS4, CZTS) is a sulfide mineral with a unique grid structure that can be obtained by replacing two iotas of In3+ in chalcopyrite with one particle of Zn2+ and one molecule of Sn4+.The components known for this mineral and its subordinates Cu2ZnSn(S,Se)4 (CZTSSe) are less hazardous and abundant on the planet, which may be advantageous for the development of additional feasible and low-cost advances.
For many years, material researchers and designers have been investigating the chance of utilizing kesterite materials to make more reasonable and feasible solar-based cells. In spite of broad endeavors toward this path, the most powerful proficiency achieved by kesterite sun-based cells is 12.6%, which was first detailed in 2013.
Scientists at Nanjing College of Posts and Media Communications, Fudan College, the Chinese Institute of Sciences, and the College of Washington have as of late outperformed this very long-term record, fostering a superior performing kesterite/Cds interface that could empower the making of sun-based cells with a 13% proficiency. This connection point, introduced in a paper distributed in Nature Energy, could enable the making of more effective and better performing kesterite solar cells.
“The fundamental goal of the Nature publication was to understand the formation of the defective kesterite/CdS heterojunction interface and how heat annealing dramatically reduces the concentration of defects.”
Hao Xin, one of the researchers who carried out the study,
“The Nature Energy paper expands on our previous work, which demonstrated that the kesterites Cu2ZnSn(S,Se)4 (CZTSSe) and (Ag,Cu)2ZnSn(S,Se)4 (ACZTSSe) safeguards created from the SnCl4-based DMSO arrangement show improved gadget execution with the decreased recombination close kesterite/Cds interface,” Hao Xin, one of”The essential goal of the Nature paper was to comprehend the first of the faulty heterojunction connection points of kesterite/Cds and how warm tempering incredibly lessens the grouping of the deformities.”
In their tests, Xin and his partners showed that a kesterite/Cds heterojunction is built on a Zn-unfortunate surface, as Zn2+ breaks up during the compound shower statement process. As a result, Cd2+ has a recently involved Zn site, and Zn2+ is re-kept into Cds, resulting in a faulty connection point with a jumbled grid.
To remake the epitaxial interface, the scientists applied a method known as low temperature strengthening to the kesterite/Cds intersection. This method permitted them to drive the movement of Cd2+ from the safeguard layer back to the CdS site and Zn2+ from the safeguard mass to the material’s surface.
“The forerunner films (created from SnCl4 based DMSO arrangement) have kesterite (Cu2ZnSnS4, CZTS) structures previously framed, which takes an immediate stage change grain development system to shape CZTSSe/ACZTSSe safeguard films during selenization,” Xin said. “Our methodology evades optional stages and hence makes for a uniform and less flawed safeguard.”
The scientists assessed the kesterite/Cds interface they made in a progression of tests and found that it beat recently made kesterite interfaces. Their underlying creation strategy was found to essentially further develop the open-circuit voltage and fill element of sun-based cell gadgets, accomplishing ensured efficiencies of 12.96% over a small region (0.11cm2) and 11.7% over a huge region (1.1cm2).
Later on, the trial strategies contrived by Xin and his partners could enable the advancement of kesterite/Cds connects with more uniform safeguard films. These connection points could thus be utilized to foster better performing kesterite sun-based cells.
Xin added, “Interestingly, we reveal how the kesterite/Cds heterojunction is built (in view of the Zn-unfortunate surface) and why it is faulty (because of control of Cd2+ on Zn opening), which appears differently in relation to CIGS, from which kesterite is acquired.” “In our next work, we intend to further design the deformities of kesterites.”
More information: Yuancai Gong et al, Elemental de-mixing-induced epitaxial kesterite/CdS interface enabling 13%-efficiency kesterite solar cells, Nature Energy (2022). DOI: 10.1038/s41560-022-01132-4
Yuancai Gong et al, Sn4+ precursor enables 12.4% efficient kesterite solar cell from DMSO solution with open circuit voltage deficit below 0.30 V, Science China Materials (2020). DOI: 10.1007/s40843-020-1408-x
Yuancai Gong et al, Identifying the origin of the Voc deficit of kesterite solar cells from the two grain growth mechanisms induced by Sn2+ and Sn4+ precursors in DMSO solution, Energy & Environmental Science (2021). DOI: 10.1039/D0EE03702H
