High Performance Amorphous Metal-Oxide Semiconductors Thin-Film Passive and Active Pixel Sensors

In this paper, for the first time, we report on high performance amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) based passive pixel sensor (PPS) and active pixel sensor (APS) circuits. Experimental results show that single-TFT PPS with a pitch length of 50 mu m can achieve a signal charge gain approaching to unity (Gain=0.93) under a fast readout time of 20 mu s and a dynamic range of 40dB. APS based on three a-IGZO TFTs, with a pitch length of similar to 100 mu m, established a high dynamic range of more than 60dB. 2-TFTs half active pixel sensor (H-APS) testing circuits are also designed to investigate the voltage gain (A(V)=Delta(VOUT)/Delta V-G) properties for the APS circuit in this work. For the a-IGZO APS, AV is measured to be similar to 1.25, and through normalization of the pixel capacitance (C-PIX) to a common value of 5pF, a large signal charge gain of 25 is obtained.