A novel structure of &bgr;‐SiC/p‐Si has been reported to emit visible electroluminescence (EL). The &bgr;‐SiC is grown directly on a Si substrate by rapid thermal chemical vapor deposition (RTCVD) technology. The mechanism of EL emission is shown as a porous silicon (PS) layer. The PS is formed unintentionally at &bgr;‐SiC/p‐Si interface owing to a large lattice mismatch (20%) between &bgr;‐SiC and Si substrates. In addition, the heterojunction diode exhibits excellent rectifying behavior. The ideality factornand rectification ratio at 1.0 V are 1.8 and 340, respectively.