In-pixel temperature sensor for high-luminance active matrix micro-light-emitting diode display using low-temperature polycrystalline silicon and oxide thin-film-transistors

We propose an in-pixel temperature sensor using low-temperature polycrystalline silicon and oxide (LTPO) thin-film transistor (TFTs) for high-luminance active matrix (AM) micro-light-emitting diode (LED) displays. By taking advantage of the different off-current characteristics of p-type LTPS TFTs and n-type a-IGZO TFTs under temperature change, we designed and fabricated a temperature sensor consists of only LTPO TFTs without additional sensing component or material. The fabricated sensor exhibits excellent temperature sensitivity of up to 71.8 mV/degrees C. In addition, a 64 x 64 temperature sensor array with 3T sensing pixel and integrated gate driver has also been fabricated, which demonstrates potential approach for maxing out the performance of high-luminance AM micro-LED display with real-time in-pixel temperature monitoring.