Uncovering opto-electro-thermo-mechanical couplings for optoelectronic materials: From nonlinear statics to dynamics

: Metal halide perovskites are promising candidates for photovoltaics and optoelectronics, yet their structural behavior, particularly deformation and stability under coupled optical, electrical, thermal, and mechanical fields remains unclear. Capturing this field-structure feedback is therefore crucial for predicting nonlinear responses and assessing mechanical reliability under realistic operating conditions. In this paper, a fully coupled opto-electro-thermo-mechanical constitutive framework is developed for MAPbI 3 -type lead halide perovskites by unifying multi-field-induced stress, electric displacement, light pressure sensitivity, and thermal entropy density. Building on this coupled model, a rectangular perovskite plate is analyzed as a representative platform using Mindlin-Reissner kinematics and von Kármán nonlinearity. The total energy of the coupled system is incorporated into Hamilton’s principle to derive the governing equations, which are nondimensionalized and solved using the differential quadrature method and an iterative eigenvalue scheme. Comparative validation is performed for the electrical and optical properties of MAPbI 3 , and the mechanical responses under multi-physics fields are further benchmarked, thereby ensuring the accuracy of both the coupled model and the numerical methods. The results reveal two competing optical pathways. Illumination-driven optoelectrical coupling, dominated by electric displacement, controls the high-field regime by amplifying deflection, reducing buckling capacity, and inducing dynamic softening. In contrast, the optomechanical pathway associated with light pressure sensitivity mainly contributes an internal optical-feedback term that increases the baseline tangent stiffness. Neglecting this pathway therefore overestimates field-induced instability and mechanical degradation.