A light-emitting diode (LED) device (e.g., AlGaInP LED) includes a transparent substrate, an epitaxial structure defining an isolation trench and an epitaxial structure, an insulating passivation layer, a P electrode and an N electrode. The epitaxial structure is disposed above the transparent substrate. The isolation trench divides the epitaxial structure into a first portion and a second portion. The at least one through hole extends through the first portion. At least a portion of the insulating passivation layer is disposed in the isolation trench. The P electrode is disposed above the first portion of the epitaxial structure and in the at least one through hole. The N electrode is disposed above the second portion of the epitaxial structure. A top surface of the P electrode is horizontally aligned with a top surface of the N electrode.