Zero thermal expansion (ZTE) is a desired but rare material property. Herein we report a unique family of inorganic-organic hybrid semiconductors with general formula [ZnSe-(L) 0.5 ] (L = organic diamine) that exhibit nearly-zero thermal expansion along the layer-stacking axis in the temperature range of 5-300 K. The unit cell parameters and crystal structures of [ZnSe(en) 0.5 ], [ZnSe(pda) 0.5 ], [ZnSe(bda) 0.5 ], and [ZnSe(ptda) 0.5 ] (en = ethylenediamine, pda = propanediam-[a]