Abstract The experimental observation of internal quantum efficiencies above unity in crystalline silicon solar cells has brought up the question whether the generation of multiple electron/hole pairs has to be taken into consideration also in solar cells based on direct gap amorphous semiconductors. To study photogenerated carrier dynamics, we have applied Intensity Modulated Photocurrent Spectroscopy (IMPS) to hydrogenated amorphous silicon p-i-n solar cells. In the reverse voltage bias region at low illumination intensities it has been observed that the DC quantum yield and the low frequency limit of the AC quantum yield Y increases significantly above unity with decreasing light intensity, indicating that more than one electron per photon is detected in the external circuit. This phenomenon can occur due to the presence of dangling bond defect centers in the band gap, which have an amphoteric character and can enhance the photocurrent due to trapping and thermal emission processes of photogenerated carriers.