Sensor Arrays With Integrated Track and Hold Circuits Manufactured on Glass

Abstract

This paper shows the realization and characterization of current and light sensor arrays on glass with integrated track and hold circuits, which enable the recording of all sensing elements at the same time. The current detection circuitry and the holding elements consist of thin-film devices using the metal-oxide semiconductor amorphous indium gallium zinc oxide (a-IGZO). Moreover, the array control and readout circuitry is also realized by a-IGZO thin-film transistors (TFTs), creating decoders and multiplexers. This makes the sensor arrays easy to combine with display backplanes using a-IGZO TFTs. An example is the low-temperature polycrystalline oxid (LTPO) backplane used in OLED displays. In addition, the arrays with phototransistors are utilized to spatially resolve the radiation pattern of a LED at $385\text{nm}$. The integration of track and hold circuits avoids the disadvantage of readout time differences between sensors of an array caused by slow response times caused by the persistent photoconductive effect in a-IGZO.