Scientists from China’s Peking University have developed a new method for making perovskite films for PV applications in an ambient atmosphere.
The technique, described in the paper A prenucleation strategy for ambient fabrication of perovskite solar cells with high device performance uniformity, published in Nature Communications, aims to avoid the efficiency loss caused by humidity linked to the interactions of ambient water and oxygen with the perovskite precursors and substrate used during cell production.
Pre-nucleation consists of the controlled formation of a vast number of lead complexes – “pre-nucleation clusters” – during the wet sample spinning process of perovskite film manufacture.
Lead in c-Si modules
pv magazine has discussed the use of lead in crystalline solar modules as part of our global UP sustainability initiative. Check out the October, November and December print issues of the magazine to read our UP coverage. To join the conversation, contact up@pv-magazine.com.
The approach suggested by the Peking team was conceived as a way to design chemical reaction routes, according to the researchers. “Although these chemical reaction routes showed potential to realize the ambient fabrication of PVSCs [PV solar cells], the inherent mechanisms are still unclear and the variations of device performance to environmental conditions need to be improved,” stated the group.
The researchers said the formation of lead complexes is facilitated by the presence of water in conventional manufacturing processes. To avoid the presence of excess water, the Peking group used a burst of lead complexes to facilitate, and prolong, nucleation of the intermediate crystallites. Uncontrolled growth of such crystallites can affect the efficiency and durability of solar cells.
Popular content
Controlled growth
Unlike the conventional method of solvent dripping in ambient air, which leads to large intermediate crystals, the method proposed by the Peking group is said to deliver smaller crystals in the wet films which are easier to convert into perovskite. “As a result, the pre-nucleation method made the wet film transform more easily and more rapidly from the transparent intermediate to the [more efficient] black perovskite [form], even without annealing,” the researchers said, referring to the process of heating and then slowly cooling to increase durability.
The Peking group claims this process has enabled the production of a perovskite cell with a peak conversion efficiency of 21.5% and an average of 18.8%. In durability terms, the researchers said the cell lost around 10% of its efficiency after 100 days of storage.
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: editors@pv-magazine.com.
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.