First-Principles Investigation of Structural Stability and Optoelectronic Properties of Lead-Free CsSnₓGe₁₋ₓI₃ Mixed-Halide Perovskites for Advanced Optoelectronic Applications. njap [Internet]. 2026 Jul. 24 [cited 2026 Jul. 28];2(2):160-8. Available from: https://njap.nipngr.org/index.php/njap/article/view/48