In this work we present large area AlGaAs photochodes for detecting the luminescent light of crystal scintillators in detectors of ionizing radiation, fabricated by low-temperature variant of the liquid-phase epitaxy (LPE) method. They exhibit a low leakage Current (lower than 10(-12) A/cm(2)), a high quantum efficiency for wide spectral range (400-900 nm) and a high operating temperature (up to 120 degreesC). P-i-n GaAs detectors on the base of high purity LPE GaAs material grown by LPE are Suggested as an alternative to those oil the base of semi-insulating (SI) GaAs material. The use of high purity GaAs instead SI GaAs material much reduces charge carrier trap concentrations and make it possible for p-i-n photodiode to obtain a high charge collection efficiency at low bias voltages. The calculated electrical characteristics show that low capacitance and low dark current can be realised in these photochodes. (C) 2003 Elsevier Ltd. All rights reserved.