Abstract: The Non-Carrier-Injection (NCI) mode is a new electroluminescence strategy that does not need external charge injection. NCI devices under AC fields involve lattice vibrations and piezoelectric coupling, whose effects on emission are not fully understood. Here, core-shell quantum dots are studied using finite element simulations. A phonon-based empirical model is applied to quantify how temperature and piezoelectric effects influence energy bands, carrier distribution, and efficiency. Results show that higher temperature reduces electron concentration via enhanced electron-phonon scattering, causing efficiency loss. Piezoelectric fields modulate energy bands and trap electrons at the core-shell interface, lowering emission. This work provides theoretical insight for optimizing NCI quantum-dot devices.