About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
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| Symposium
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TMS Frontiers of Materials Award Symposium: Harnessing Charged and Chemical Defects for Exceptional Structural and Functional Properties
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| Presentation Title |
On the Embrittlement of Grain Boundaries in CdTe from CdCl2 Passivation
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| Author(s) |
Jonathan Cappola, Joshua Carbajal, Feng Yan, Lin Li |
| On-Site Speaker (Planned) |
Jonathan Cappola |
| Abstract Scope |
Passivation of grain boundaries (GBs) in polycrystalline CdTe thin films via post-treatment of annealing in a CdCl2 environment has been critical in the rapid improvement of solar conversion efficiency to upwards of 22%. The deleterious deep-gap states associated with dangling bonds at the GBs are shifted into the valence band by preferential segregation of Cl as substitutional impurities at Te sites. However, such strong solute segregation may also induce embrittlement of the GBs in CdTe, raising concerns for flexible solar cells. To assess whether passivation compromises mechanical integrity, we examine the embrittlement potency of Cl in CdTe at a representative Σ3<110>(112) STGB using ab-initio tensile simulations. By combining these simulations with the excess-energy approach, we provide a reliable assessment of the influence of Cl impurities on the GB strength of CdTe. |