2.4.1 Metal Chalcogenide 1.0 and 2.0​

Tasks:

• Progress control of 1D-3D bulk defects and heterointerface architecture for reduced recombination.

•  Develop 2D device simulation model to understand grain boundary and interface recombination and integrate the 2D simulation model and advanced characterisations to understand the dominant performance loss mechanisms.

•  Integrate high band gap top cells, low bandgap chalcogenide bottom cell, as well as transparent electrode and intermediate layer technology (detailed in PP3.4), Targeting >20% efficiency of chalcogenides-1.0 and -2.0 and >27% efficiency flexible tandem cells.

•  Develop cost-effective and robust Cd-free buffer options with suitable band alignment for green high bandgap and low bandgap chalcogenide-1.0&2.0. Cd-free buffer options by various methods (e.g., CBD, sputtering and ALD) for efficiency, cost, and stability.

•  Evaluate the alkaline-induced LID issue where sodium is a must-have for high efficiency metal chalcogenides at both cell and module level. This typical LID issue will be tackled by understanding the roles and mobility of alkaline ions under different stress (illumination, heat) by advanced nanoscale characterisation, as well as our patented strategies of modulating alkaline amount of bulk chalcogenide. will be evaluated.

•  Explore bifacial architectures for chalcogenides. TCOs combined with barrier layer and associated back contact interface design, minimising the elemental interdiffusion while enhancing carrier collection, will be the key focus when translated to bifacial cells.