The current through silicon emitter-base (npn) junctions is measured for forward and reverse polarizations. The I-V characteristics are presented for unirradiated samples at different temperatures. For forward bias, we have studied the reverse saturation current (I_S), the series resistance (R_S) and the ideality factor (n) as function of temperature. The temperature effect is more consistent with the generation current from the space charge region. For reverse polarization, we have studied Ln (I_R/T^1/2) as function of the reciprocal temperature and we found 0.29 eV for the activation energy which is in good agreement with the result obtained from electroluminescence (EL) spectra.