The manipulation of quantum states via mechanical strain offers a pathway to engineer topological excitons in soft semiconductors. Here, we present a theoretical framework that shows that helical strain transforms lead halide perovskite quantum dots (QDs) into a platform for topological excitonics. Using a first-principles-informed framework combining strain-modulated Lamé eigenstates and non-perturbative Coulomb interactions, we identify a strain-driven topological transition at critical ellipticity \(k = 0.59 \pm 0.02\) , (corresponding to ≈ 2% torsional strain) marked by inversion of the exciton Chern number ( \(C = 0 \to 1\) ) and π-Berry phase accumulation. Quantitative calculations yield an exciton binding-energy enhancement up to 45 meV and photoluminescence (PL) redshifts of ≈ 72 meV, in agreement with experimental data. The computed deformation potential (− 0.8 eV/% strain), group-velocity scaling (v ∝ k1.7), and Chern-number inversion confirm a strain-driven topological crossover supported by Berry-phase accumulation. Comparison with reported PL and diffusion measurements validates the predictive accuracy of the Lamé-Coulomb formalism, which bridges continuum elasticity with quantum confinement. These findings proposes perovskite QDs as experimentally accessible hosts of strain-tunable topological excitons, enabling reconfigurable quantum-photonic and optoelectronic devices based on mechanically programmable excitonic states.
