Organic electroluminescent device and fabrication method thereof

A method for forming an organic electro luminescent device, comprising:

• providing a substrate comprising a first control area and a second control area;
• forming a polysilicon active layer on the first control area;
• forming a first conductivity type source/drain area in the polysilicon active layer;
• forming a first dielectric layer on the polysilicon active layer serving as a first gate dielectric layer;
• forming a first gate and a second gate on the polysilicon active layer and the second control area, respectively, wherein the first gate and the first conductivity type source/drain area constitute a first conductivity type thin film transistor serving as a switch element;
• forming a second dielectric layer on the first gate and the second gate serving as a second gate dielectric layer;
• forming a micro-crystal silicon active layer over the second gate;
• and
• forming a second conductivity type source/drain area in the micro-crystal silicon active layer, wherein the second gate and the second conductivity type source/drain area constitute a second conductivity type thin film transistor serving as a driving element.