OLED touch panel and method of forming the same

A method of forming an organic light emitting diode (OLED) touch panel, comprising:

• providing a substrate, including at least a pixel region on the substrate, and including a display region and a light sensing region in the pixel region;
• forming a first thin film transistor and a second thin film transistor in the display region of the substrate and in the light sensing region of the substrate respectively, wherein the second thin film transistor includes a first source/drain electrode and a second source/drain electrode;
• forming a readout line on the substrate, wherein the first source/drain electrode of the second thin film transistor is electrically connected to the readout line;
• forming a first conductive film on the first thin film transistor and the second thin film transistor;
• patterning the first conductive film to form a first bottom electrode and a second bottom electrode, wherein the first bottom electrode and the second bottom electrode are located in the display region and in the light sensing region respectively, and the first bottom electrode and the second bottom electrode are electrically connected to the first thin film transistor and the second thin film transistor respectively;
• forming a patterned organic light emitting layer on the first bottom electrode;
• forming a patterned light sensing silicon-rich dielectric layer on the second bottom electrode;
• forming a second conductive film on the patterned organic light emitting layer and the patterned light sensing silicon-rich dielectric layer;
• and
• patterning the second conductive film to form a first top electrode and a second top electrode so as to form an optical sensor, wherein the first top electrode and the second top electrode are located on the patterned organic light emitting layer and on the patterned light sensing silicon-rich dielectric layer respectively, and the second top electrode is electrically connected to a voltage, wherein the second source/drain electrode of the second thin film transistor is electrically connected to the second bottom electrode of the optical sensor.