研究目的

Investigating the reaction pathway for efficient CZTSe solar cells from alloyed Cu-Sn precursor via a Cu-rich selenization stage to prevent Sn loss and control the composition and quality of the grown material.

研究成果

The study concludes that starting with the SEAL precursor and selenization without alloy segregation provides a route of kesterite CZTSe formation without XRF-detectable Sn-loss. The formation and subsequent evaporation of SnSe2-x phases in the reaction is significantly reduced, preventing Sn loss from the layer during the selenization process. Providing extra SnSe2-x supply during the high temperature stage of the selenization process leads to an in-process composition shift in the sample from initially Cu-rich to a Cu-poor. This allows for the design of a defined reaction and composition pathway throughout the process, which could be a novel approach for reaching higher solar cell efficiencies.

研究不足

The technical and application constraints include the high volatility of binary selenides at necessary annealing temperatures, which challenges the control of the composition and quality of the grown material. Potential areas for optimization include the variation in initial and final composition, and the investigation of the in-process compositional shift from Cu-rich to Cu-poor and its impact on the resulting material properties.