Engineering Analysis with Boundary Elements 145 (2022) 396–403 Available online 10 October 2022 0955-7997/© 2022 Elsevier Ltd. All rights reserved. Develop a molecular dynamics approach to simulate the single-/multi-layer CsGeX 3 (X = I, Cl, and Br) perovskite stress-strain structure at different temperatures and pressures for solar cell in building energy management Jueru Huang a, * , Dmitry D. Koroteev b , Marina Rynkovskaya a a Department of Civil Engineering, Peoples Friendship University of Russia (RUDN University), Moscow, Russia b Moscow State University of Civil Engineering, Moscow, Russia A R T I C L E INFO Keywords: CsGeX 3 Molecular dynamic Stress – strain Elastic constants Solar cell ABSTRACT In this study, the mechanical characteristics of single-/multi-layer CsGeX 3 (X = I, Cl, and Br) were analyzed employing a software application known as LAMMPS. In the simulation, making use of the LAMMPS calculation code serves as the foundation for determining the various mechanical characteristics. A two-axis test is applied to the simulated samples in this calculation code, the Young’s modulus as well as the strain-stress curve of atomic structures are reported. The maximum stress (ultimate strength) for single-/multi-layer CsGeX 3 (X = Br, I, and Cl) structure obtained with applying load in the X and Y directions. Molecular dynamics simulation using the LAMMPS software revealed that this atomic structure had the required mechanical characteristics to manufac- ture perovskite solar cells. For CsGeX 3 , here estimated the final strength, Elastic constants, Poisson’s ratio, shear modulus, Young’s modulus, and bulk modulus of the simulated atomic structures. The great precision of this simulation study was shown by the fact that the computed values for Poisson ratio and Young’s modulus closely matched the previously reported experimental results. This theoretical work thus significantly addresses the existing needs on the subject of prolonging the durability of devices that produce and use perovskites. 1. Introduction Perovskite solar cells are suitable for the next generations of solar cells because their organic and inorganic belongings [1]. Lead-based perovskite material (CH 3 NH 3 PbI 3 ) performs well in solar cells due to its proper bandgap [2–4]. In 2009, perovskite solar cells had an effi- ciency of 3.8%, according to their measurements, which increased to 25.5% in 2020 and is still increasing [5–7]. The toxic nature of lead-containing compounds has prevented their commercial use in solar cell fabrication, so lead-free and tin-based compounds are suitable for solar cell fabrication because their very low levels of toxicity, ideal bandgap, carrier lifetime, with a great degree of mobility of carriers [8, 9]. CH 3 NH 3 SnI 3 , with a bandgap of about 1.3 eV, is used in the pro- duction of perovskite solar cells, which are non-toxic [10]. Germanium is included among the most abundant metals in the earth’s crust, and its toxicity is very low [11]. Additionally, using CH 3 NH 3 GeI 3 and CsGeI 3 in photovoltaic devices [12,13], its magnetic properties can be used in light control and low-power applications such as magneto-optical in- formation storage devices [14,15]. Recently, an alternative to Pb with Sn has been dominated for Halide perovskite nanocrystals and nano- plates [16,17]. One of the essential features of many perovskite struc- tures is the capacity to maintain control over the energy gap. One of the methods to control the energy gap is to change the diodes used in these atomic structures [18,19]. Another notable feature of this group of structures, as mentioned earlier, is the presence of a diffusion length of a magnitude of micrometers for charge carriers (electrons and holes), which indicates the ability of these materials to use them as the layer of solar cells that is responsible for absorbing light is a thin layer. The physical basis of these promising properties can be deciphered using scientific research [20,21]. According to a recent study, the separation of charge carriers in perovskite structures is one of the properties of these structures, which is called bipolar property, so it can be said that the energy of electron dependence and holes in the oxytocin structure is as low as at room temperature these charge carriers move separately [22,23]. In addition to the many practical benefits of perovskite solar cells, there are challenges in preparing these cells. The most critical challenges in building solar cells based on perovskite compounds are: Reducing the thickness of metal oxide used in these cells because * Corresponding author. E-mail address: huangjueru52@sina.com (J. Huang). Contents lists available at ScienceDirect Engineering Analysis with Boundary Elements journal homepage: www.elsevier.com/locate/enganabound https://doi.org/10.1016/j.enganabound.2022.09.027 Received 22 August 2022; Received in revised form 23 September 2022; Accepted 24 September 2022