Many MindedA chloride layer helps organic solar modules hold their efficiency
Researchers at the Ningbo Institute of Materials Technology and Engineering, part of the Chinese Academy of Sciences, have described a way to make organic solar cells both more efficient and more durable. The work appears in the journal Joule. Small-area cells reached 20.4% power conversion efficiency. Modules with a 15.6 cm² aperture area reached 18.8% active-area efficiency, which corresponding author Prof. Liu Quan called a record.
The method adds a vacuum-deposited indium chloride (InClx) interlayer between the electrode and the hole-transport layer. It triggers a ligand exchange and forms a multidentate indium-oxygen-phosphorus coordination network. That network anchors self-assembled monolayers densely and uniformly. The paper says that forming dense, stable contacts of this kind on indium tin oxide has held back commercially viable organic modules. Devices kept over 85% of their initial efficiency after 2,000 hours of maximum power point tracking at 25 C. The paper also reports strong batch-to-batch reproducibility, including on large-area substrates.
This matters for energy because organic photovoltaics point toward solar that is lightweight, flexible and cheap to make. That could put power generation on surfaces that rigid silicon panels can't easily use. Until now, the weak point has been the gap between lab efficiency and a module that lasts. A fix at the contact layer addresses that gap directly.
The caveats are significant. The record claim comes from the author, not independent verification. Stability was tested only at 25 C under lab conditions, so field durability is unproven. A 15.6 cm² module is far from commercial size, and the claim of resolving the efficiency, stability and scalability trade-off is the authors' own conclusion. Watch for independent replication, heat and humidity testing, and larger modules.
Source: pv magazine