Pixel unit and method of manufacturing the same, array substrate and display device

A method of manufacturing a pixel unit, including steps of:

• forming a polysilicon layer on a substrate;
• performing a single patterning process on the polysilicon layer so as to form an active region of a thin film transistor and a lower electrode region of a storage capacitor;
• forming a first insulating layer on the polysilicon layer, portions of the first insulating layer being used as a gate insulating layer of the thin film transistor and a dielectric layer of the storage capacitor;
• performing a single doping process on the active region and the lower electrode region so as to form heavily doped regions of the thin film transistor and a lower electrode of the storage capacitor respectively;
• forming a gate of the thin film transistor and an upper electrode of the storage capacitor on the first insulating layer;
• forming, before performing an ion activation treatment in the heavily doped regions and the lower electrode region, a second insulating layer on the first insulating layer, the gate and the upper electrode;
• and
• after forming the second insulating layer, processing the substrate at a temperature above 400° C. so that an ion activation reaction and a hydrogenation reaction occur in the active region and the lower electrode region.