A light-emitting diode is made by closely contacting an n(+)-type porous Si him with chemically polymerized polyaniline inside the pores of Si. The tight filling of the Si pores by polyaniline was testified by XPS depth profiling analysis. The diode shows a rectifying I-V characteristic, has a series resistance of 2 Omega and passes out high current densities under a forward bias of only a few volts. The diode efficiently emits red light under a forward bias voltage exceeding 3 V.