TY - JOUR AU - Kessler, Jan AU - Calcavecchia, Francesco AU - Kühne, Thomas D. ID - 23598 JF - Advanced Theory and Simulations SN - 2513-0390 TI - Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo ER - TY - JOUR AU - Kessler, Jan AU - Calcavecchia, Francesco AU - Kühne, Thomas ID - 33649 IS - 4 JF - Advanced Theory and Simulations KW - Multidisciplinary KW - Modeling and Simulation KW - Numerical Analysis KW - Statistics and Probability SN - 2513-0390 TI - Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo VL - 4 ER - TY - JOUR AB - Adaptive kinetic Monte Carlo simulation (aKMC) is employed to study the dynamics and the diffusion of point defects in the CuInSe2 lattice. The aKMC results show that lighter alkali atoms can diffuse into the CuInSe2 grains, whereas the diffusion of heavier alkali atoms is limited to the Cu-poor region of the absorber. The key difference between the diffusion of lighter and heavier alkali elements is the energy barrier of the ion exchange between alkali interstitial atoms and Cu. For lighter alkali atoms like Na, the interstitial diffusion and the ion-exchange mechanism have comparable energy barriers. Therefore, Na interstitial atoms can diffuse into the grains and replace Cu atoms in the CuInSe2 lattice. In contrast to Na, the ion-exchange mechanism occurs spontaneously for heavier alkali atoms like Rb and the further diffusion of these atoms depends on the availability of Cu vacancies. The outdiffusion of alkali substitutional atoms from the grains results in the formation of Cu vacancies which in turn increases the hole concentration in the absorber. In this respect, Na is more efficient than Rb due to the higher concentration of Na substitutional defects in the CuInSe2 grains. AU - Kormath Madam Raghupathy, Ramya AU - Kühne, Thomas AU - Henkelman, Graeme AU - Mirhosseini, Hossein ID - 15725 JF - Advanced Theory and Simulations SN - 2513-0390 TI - Alkali Atoms Diffusion Mechanism in CuInSe 2 Explained by Kinetic Monte Carlo Simulations ER -