Pixellated Perovskite Photodiode on IGZO Thin Film Transistor Backplane for Low Dose Indirect X-Ray Detection
Taoyu Zou, Xiang Ben, Yangbing Xu, Ya Wang, Chuan Liu, Jun Chen, Kai Wang, Qing Dai, Shengdong Zhang, Yong‐Young Noh, Hang Zhou
Abstract
The integration of perovskite photodetectors with thin-film transistor (TFT) backplane or complementary metal-oxide-semiconductor CMOS circuit is a key step towards prototyping perovskite-based image sensors. Here, we demonstrate a pixel configuration for indirect X-ray detection comprising of IGZO TFTs and perovskite photodiodes (PDs). The perovskite photodiode is patterned by a two-step deposition method. Our integrated TFT/PD pixel shows a weak light detection capability down to 4 nW cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> and a fast-transient response to the pulse light and gate switching. Combining with a CsI scintillator, the integrated pixel achieves a specific X-ray sensitivity of 8.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8.2 \times 10^{2} \mu \mathrm{C} \mathrm{mGy}_{\text {air }}^{-1} \mathrm{~cm}^{-3}$ </tex-math></inline-formula> . Theoretically, with a state-of-the-art scintillator, the new pixel can provide a detectable signal for X-ray imaging at a dose rate as low as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10 \mu \mathrm{Gy}_{\text {air }} \mathrm{s}^{-1}$ </tex-math></inline-formula> . This work provides an advanced pixel design for high resolution, high sensitivity, and high frame-rate flat-panel imager.