Enhancing band-edge nonradiative recombination lifetimes in I-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>II</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>-III-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">

Balancing efficiency enhancement and cost reduction is crucial for advancing solar energy and photovoltaic devices. One of the primary sources of energy loss, leading to reduced efficiency, is nonradiative electron-hole recombination within these devices. In this study, we comprehensively investigated the nonradiative properties of excited-state carriers in quaternary Kesterite (KS) and Stannite (ST) phase $\mathrm{I}\text{\ensuremath{-}}{\mathrm{II}}_{2}\text{\ensuremath{-}}\mathrm{III}\text{\ensuremath{-}}{\mathrm{VI}}_{4}$ chalcogenide compounds using first-principles calculations combined with nonadiabatic molecular dynamics (NAMD). We identified the characteristics of chemical bond elongation, electron localization and bandgap fluctuations induced by cation modulation. Specifically, forming quaternary structures by introducing Zn and substituting $\mathrm{I}{\mathrm{n}}^{3+}$ with $\mathrm{G}{\mathrm{a}}^{3+}$ and $\mathrm{C}{\mathrm{u}}^{+}$ with $\mathrm{A}{\mathrm{g}}^{+}$ resulted in increased bandgaps. Through a detailed analysis of orbital and vibrational components, we elucidated the principles for regulating nonadiabatic coupling and carrier lifetimes, including strategies to suppress the ${t}_{2}$ orbital of I-site cations, low-frequency optical phonons and anti-Zeno effects. Compared with the KS structure, the ST structure retains higher symmetry, with suppressed low-frequency electron-vibration interactions, leading to reduced nonradiative recombination. These findings provide insights into effectively reducing nonradiative recombination processes, thereby highlighting the potential of $\mathrm{I}\text{\ensuremath{-}}{\mathrm{II}}_{2}\text{\ensuremath{-}}\mathrm{III}\text{\ensuremath{-}}{\mathrm{VI}}_{4}$ chalcogenide compounds for high-efficiency photovoltaic applications.