Pixellated Perovskite Photodiode on IGZO Thin Film Transistor Backplane for Low Dose Indirect X-Ray Detection

Abstract

The integration of perovskite photodetectors with thin-film transistor (TFT) backplane or complementary metaloxide-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-2 , 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  10 2 μC mGyair-1 cm-3. Theoretically, with a stateof-the-art scintillator, the new pixel can provide a detectable signal for X-ray imaging at a dose rate as low as 10 μGyair s-1. This work provides an advanced pixel design for high resolution, high sensitivity, and high frame-rate flat-panel imager.

Recent Development of Halide Perovskite Materials and Devices for Ionizing Radiation Detection

“…Recently, a high-performance Cu/BCP/C 70 /FAPbI 3 /CsI/poly-TPD/ITO X-ray detector was further reported, where CsI was introduced as the HTL like poly-TPD and NiO x . Besides, the IGZO TFT/perovskite p-i-n photodetector pixel combined with the CsI:Tl scintillator was demonstrated with a high sensitivity value of 8.2 × 10 5 μC Gy air –1 cm –3 for X-rays, which proposes a simple way to detect ionizing radiation …”

“…261 Besides, the IGZO TFT/perovskite pi-n photodetector pixel combined with the CsI:Tl scintillator was demonstrated with a high sensitivity value of 8.2 × 10 5 μC Gy air −1 cm −3 for X-rays, which proposes a simple way to detect ionizing radiation. 333 Thicker films and wafers require high voltage operation in order to increase the sensitivity of the detector, resulting in high power consumption, thus limiting their application into wearable and portable devices. 266 With this regard, Cs-based triple cation mixed-halide perovskite Cs 0.05 FA 0.79 MA 0.16 Pb(I 0.8 Br 0.2 ) 3 (CsFAMA) thin films with a thickness of 450 nm are constructed as a p-i-n type photodiode to realize efficient X-ray detection.…”

Solution-Processed Organic–Inorganic Semiconductor Heterostructures for Advanced Hybrid Phototransistors

“…Aside from the high responsivity and intrinsic amplification of the three-terminal structure, the phototransistor also possesses low noise and no pixel crosstalk properties, which is of great benefit to the large-area image sensor matrix and monolithic integration with other electronic components. , Figure a depicts a circuit diagram illustrating a static phototransistor array for NIR light imaging applications, where each pixel consists of only one phototransistor with the global gate electrode. A phototransistor array (10 × 10) has been reported based on an organic/inorganic heterojunction (Figure b) with large-area process compatibility and uniformity (Figure c).…”

Analog and Mixed Signal Circuit Design Techniques in Flexible Unipolar a-IGZO TFT Technology: Challenges and Recent Trends

“…There has been a strong research and industrial effort in a-IGZO TFT technology applications related to large area displays [10]- [13], flexible X-ray imagers [14]- [16], touchscreen tags [17]- [19], Radio Frequency Identification (RFID) [20], [21], Near Field Communication (NFC) tags [22]- [25], machine learning processing engines [26] and flexible microprocessors [8] in the last few years. This research was mainly focused on circuits and systems where the TFTs are used as switches, due to various challenges observed when trying to implement analog functions.…”