Theoretical insights into heteroepitaxial growth: Predicting equilibrium crystal shapes
Résumé
For decades, crystal growth has been a cornerstone of technological innovation, shaping the evolution in materials science and device engineering. The story of heteroepitaxial growth begins at the atomic scale, where nucleation dictates the evolution of advanced optoelectronic and photoelectric technolo-gies[1, 2]. In this work, we combine density functional theory calculations with advanced epitaxial growth techniques and in-situ microscopy to establish a comprehensive first-principles atomistic frame-work for predicting the Wulff-Kaischew equilibrium crystal shape (ECS) of nanocrystals integrated on dissimilar substrates. We first show how absolute surface and interface energies can be determined and analyzed as a function of chemical potential for the model case of GaP/Si [3,4]. Our results highlight the strong influence of surface passivation on the wetting behavior of GaP on Si, which favors a three-dimensional Volmer-Weber growth mode [5]. Finally, we explore the potential of a fully ab initio Wulff-Kaischew ECS approach and benchmark it directly against in-situ transmission electron microscopy experiments [6]. Applied to heterogeneous systems such as III-V/Si, this atomistic approach provides valuable predictions of the nanocrystal facets that can emerge during heterointegration, as well as the morphological changes driven by variations in thermodynamic conditions (e.g., chemical potentials). This direct theory-experiment comparison significantly advances the understanding of growth mechanisms and physical properties in hetero-integrated materials and devices. This research was supported by the French National Research NUAGES Project (Grant no. ANR-21-CE24-0006). DFT calculations were performed at FOTON Institute, and the work was granted access to the HPC resources of TGCC/CINES under the allocation A0120911434, A0140911434, and A0160911434 made by GENCI. References [1] I. Lucci, S. Charbonnier, M. Vallet, P. Turban, Y. Léger, T. Rohel, N. Bertru, A. Létoublon, J. Rodri-guez, L. Cerutti, E. Tournié, A. Ponchet, G. Patriarche, L. Pedesseau, and C. Cornet, Adv Funct Materials 28(30), 1801585 (2018). [2] C. Cornet, S. Charbonnier, I. Lucci, L. Chen, A. Létoublon, A. Alvarez, K. Tavernier, T. Rohel, R. Bernard, J.-B. Rodriguez, L. Cerutti, E. Tournié, Y. Léger, M. Bahri, G. Patriarche, L. Largeau, A. Pon-chet, P. Turban, and N. Bertru, Phys. Rev. Materials 4(5), 053401 (2020). [3] I. Lucci, S. Charbonnier, L. Pedesseau, M. Vallet, L. Cerutti, J.-B. Rodriguez, E. Tournié, R. Bernard, A. Létoublon, N. Bertru, A. Le Corre, S. Rennesson, F. Semond, G. Patriarche, L. Largeau, P. Turban, A. Ponchet, and C. Cornet, Phys. Rev. Materials 2(6), 060401(R) (2018). [4] S. Pallikkara Chandrasekharan, I. Lucci, D. Gupta, C. Cornet, and L. Pedesseau, Phys. Rev. B 108(7), 075305 (2023). [5] S. Pallikkara Chandrasekharan, D. Gupta, C. Cornet, and L. Pedesseau, Phys. Rev. B 109(4), 045304 (2024). [6] S. Pallikkara Chandrasekharan, S. Apergi, C. Wei, F. Panciera, L. Travers, G. Patriarche, J. C. Har-mand, L. Pedesseau, and C. Cornet, submitted (2025), https://doi.org/10.48550/arXiv.2506.08766.