In this article, the PVK based metal-oxide-semiconductor (MOS) capacitor structures were fabricated and the photoelectric performance of the capacitor was carried out to study the intrinsic electrical characteristic of PVK with iodine doped. The electrical hysteresis of the capacitor after iodine doping becomes larger in the dark state, which indicates that the hysteresis behavior of the PVK is caused by the mobile iodine ions. The photocurrent of iodine-doped PVK is significantly greater than that of undoped PVK under illumination, which suggests that the capacitor has better response to light and the photodetectors efficiency also increase after iodine doping. Our results provide a theoretical basis for the potential application of memory devices such as memristors under dark. Meanwhile, it provides a method to improve photodetector performance by adding an appropriate amount of iodine to the PVK precursor solution. (C) 2019 Elsevier B.V. All rights reserved.