We have fabricated erbium-doped porous silicon (PSI) devices and demonstrated stable room-temperature electroluminescence (EL) at 1.54 mum under both forward and reverse bias conditions. Erbium was infiltrated into the nanostructured matrix of PSi (less than or equal to 10(19) cm(-3)) by cathodic electrochemical migration of the ions followed by high temperature annealing (950-1100 degreesC). The devices exhibit an exponential EL dependence in both bias conditions as a function of driving current and voltage. External quantum efficiencies of 0.01% have been obtained. The EL intensity in reverse bias and the transport propel tics of the devices show large temperature dependences From the differences in temperature, electrical, and EL characteristics in forward and reverse biases, we believe that different excitation mechanisms are responsible for the EL.