This paper describes studies of hot electroluminescence from silicon transistor structures in the photon energy range 0.25 to 0.8 eV. The transistor structures n-p-n and p-n-p used to obtain the emission spectra generated at accelerating voltages low enough that only one kind of carrier was involved in the excitation. Participation of hot carriers both in direct intersubband and indirect intraband radiative transitions is discussed.