Photo-emf in the range hv = 0.76 − 1.35 eV was found in p-i-n structures produced from undoped GaAs crystals with known parameters; the current sensitivities in the impurity and intrinsic (hv > 1.35 eV) regions were comparable. It was proven that the impurity photovoltaic effect results from EL2 and EL3 structural defects creating deep donor levels in the forbidden zone. Calculations were performed that justified the possibility of observing this effect on the investigated structures.
72.80.Ey III-V and II-VI semiconductors
$^1$Faculty of Physics, Moscow State University, Moscow, 119991, Russia
$^2$Institute for Nuclear Research, Russian Academy of Sciences, Moscow, Russia