We have grown Al‐free reliable 877 nm In0.49Ga0.51P/GaAs light‐emitting diodes (LEDs) on Si substrates by metalorganic chemical vapor deposition. The conventional Al‐containing Al0.3Ga0.7As/GaAs LEDs on Si substrates exhibit rapid degradations because of the formation of dark‐line defects (DLDs). On the contrary, the In0.49Ga0.51P layer on the GaAs/Si substrate exhibited a 300 K electron mobility of 950 cm2/V s with the carrier concentration of 3.8×1017 cm−3, no residual stress and a lower surface recombination velocity. The In0.49Ga0.51P/GaAs LED on Si shows the stable operation for more than 2000 h, which results from the suppression of the formation of DLDs. ©1995 American Institute of Physics.