The InAsSbP photodiodes are successfully fabricated by liquid-phase epitaxy and their electrical properties are analyzed in detail, It is found that the dark current is dominated by different mechanisms as the temperature range varies. When the temperature is higher than 180 K, the dark current is dominated by the diffusion mechanism when the temperature is in the range between 140 and 180 K, the generation-recombination mechanism comes to dominate: and when the temperature is lower than 140 K the tunneling mechanism dominates instead. The zero-bias resistance and diode area product, R(0)A, is about 2.9 x 10(6) Omega cm(2) at 80 K and degrades to 6555 Omega cm(2) when the temperature is raised to 220 K. From the room temperature current-voltage characteristics, it demonstrates a forward bias turn-on voltage of 0.06 V with an ideality factor of 1.1 and a breakdown voltage of about -2.3 V. Additionally, from the capacitance-voltage characteristics, the built-in potential is found to be about 0.28 V. (C) 2002 Elsevier Science Ltd. All rights reserved.