In order to check our hypothesis, firstly, we used basin hopping as described in Section II to understand the segregation of aluminum in the grain boundary, for up to 4 aluminum per GB. Aluminum is allowed to substitute in place of GB silicon atoms. The number of aluminum substituted and their positions are chosen randomly in each step. Each basin hopping is run for 100 steps. The results of basin hopping for the 4 aluminum per GB case are represented in Figure . From Figure , we can observe that higher energy states are attained throughout the run, switching from one to the other, enabling a wide exploration window. Moreover, a broad range of energies ( 0.7 eV -1.1 eV) are covered in the run as can be seen in Figure . The resulting global minimum has a characteristic feature, i.e., all the aluminum are in a single layer. This is a consequence of the phase diagram of siliconaluminum, where aluminum has very low solubility in silicon, and therefore aluminum atoms prefer to accumulate together. After identifying the optimal aluminum segregation configurations for different numbers of aluminum, our subsequent step involved conducting GB sliding simulations using these configurations. Each simulation consisted of 20 steps, with each step corresponding to a relative displacement of 0.773 Å, similar to the one used for pure Si GB. The results from GB sliding simulations for the scenario with four aluminum atoms per GB are visually presented in Figure . Several significant differences between GB sliding with and without aluminum are discernible: (a) The sliding barrier is remarkably lowered to 0.0385 eV/ Å², representing about 12% of the case without aluminum as can be seen in Figure . Moreover, this value is merely 40% of the interface energy of the undeformed GB with aluminum. (b)