Researchers from the Northwestern Polytechnical University, in China, have developed a planar thin-film solar cell based on antimony trisulfide (Sb2S3) with a power conversion efficiency of 5.84%. As a way of comparison, most of the antimony trisulfide cells developed to date have efficiencies close to 4%.
This kind of cell typology has, so far, been far from reaching commercial production, due to the low crystallinity and high resistivity of the Sb2S3 film, which affects the device's performance in terms of efficiency. Sb2S3, however, has a good bandgap, ranging from 1.70 to 1.90 eV, and a remarkable light absorption coefficient, and the scientists built their device by applying an additive known as 4-Chloro3-nitrobenzenesulfonyl Chloride (CSCl), which they claim has been able to alleviate these issues.
The additive was spin-coated on a titanium oxide (TiO2) substrate and annealed to crystallization. Spiro-OMeTAD was used for the hole transport layer. “The introduction of CSCl enhances the crystallinity of Sb2S3 film with [a] large grain size,” they explained, in the paper Effective additive for enhancing the performance of Sb2S3 planar thin film solar cells, which was recently published in The Journal of Materiomics. “And the two terminal Cl of CSCl molecul[es] have interaction with Sb atoms, which is conducive to increasing electron density around Sb atoms.”
Furthermore, the scientists explained the use of CSCl did not change the thicknesses of Sb2S3 film and that it raises the Fermi levels of Sb2S3 film, which in turn increases the driving force for the electron transport from the cell's Sb2S3 and TiO2 layers. The Fermi levels define the efficient conversion of the energy of radiation into electrochemical energy.
Tested under a standard illumination of AM 1.5G, two devices with concentrations of 0.5% and 3% CSCl additive showed an average power conversion efficiency of 4.35% and 4.98%, respectively. When the CSCl concentration was set at 1.5%, the cell achieved an efficiency of 5.84%, an open-circuit voltage of 0.62 V, a short-circuit current density of 15.85 mA cm2 and a fill factor of 59.61%. “The Sb2S3 films with 0.5%, 1.5%, [and] 3% CSCl additive show an obvious improvement in the light absorption capacity, which originates from the enhanced crystallinity of Sb2S3 film,” the Chinese group stated.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: firstname.lastname@example.org.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.