Using first-principles calculations, we systematically investigated the effects of hydrogenation and fluorination on the piezoelectric properties of single-layer honeycomb structures composed of group III–V compounds. Our findings reveal that both hydrogenation and fluorination effectively enhance piezoelectricity in these materials. For the initially flat structures lacking out-of-plane piezoelectricity, hydrogenation and fluorination induce structural distortions and out-of-plane polarizations, thereby generating out-of-plane piezoelectricit...
