All‐Inorganic Perovskite Photodetectors with Ultrabroad Linear Dynamic Range for Weak‐Light Imaging Applications

Abstract

introduced some new problems, such as limited application scenarios or reduced time resolution. As an important component of imaging systems, improving the performance of photodetectors (PDs) becomes a more effective way to overcome the above issues. [6-8] The weak-light detectable limit (WDL) and linear dynamic range (LDR) are two critical parameters for PDs to determine the image quality under weak-light conditions. As a main stream for image sensors, the silicon-based PDs have been widely used in digital cameras and smartphones. These PDs possess low-noise, broadband and high-detectivity properties. However, silicon has a narrow band gap of 1.1 eV leading to unwanted near-infrared response, [9] which increases the optical noise and reduces image quality. Though other semiconductors like NiO and ZnO with wider band gaps exhibit equally specific detectivity, [10,11] the WDL and LDR are less than satisfactory, along with large dark current density. Therefore, it is highly desirable to find novel high-performance PDs with low WDL and broad LDR, as well as low-cost manufacturing procedure and assembling techniques. Recently, methylammonium metal halide perovskites have been intensively studied in the field of photodetection due to their extraordinary optoelectronic properties. [12-14] The main obstacle for the high-performance device fabrication is the instability issue. [15,16] Fortunately, inorganic metal halide perovskites, CsPbX 3 (X = Cl, Br, I) exhibiting both high stability and tunable band gap, are considered to be one kind of promising materials to address the instability issues. [17] Recently, perovskites have been widely applied in the field of photoelectric imaging. [18-20] Although great improvements have been made in previous imaging applications, the image contrast and SNR of as reported inorganic perovskite PDs-based imaging are still not satisfactory, and less attention has been paid to weak-light imaging applications. Extensive attempts have been made to improve the photodetection performance of PDs. An effective strategy is introducing interfacial passivation layers by atomic layer deposition (ALD) technique. [21-24] ALD can synthesize thickness-controlled, dense, and uniform thin films at low temperature, [25] which meets the critical demands for the heterojunctions fabrication. Rehman et al. reported that J sc of Graphene/Si solar cell rises from 27.8 to 33.4 mA cm −2

Pulsed‐Laser Detectors Based on Metal Halide Perovskites

“…These devices possess relatively high responsivity of > 1 × 10 4 V W −1 over the whole range of recorded laser intensities under a 10 Hz pulsed nanosecond laser. Compared with reported ultrafast photodiodes, which normally possess LDR of over 100 dB and photocurrent responsivity of <1 A W −1 , [ 37–39 ] our devices exhibited superior responsivity. Compared with commercial pyroelectric detectors, our devices are faster and could be operated easily with voltage sensors, such as multimeter.…”

Challenges and Opportunities for CsPbBr3 Perovskites in Low- and High-Energy Radiation Detection

“…The NiO x layer assists in forming a high-quality perovskite layer via an efficient interfacial interaction at the substrate/perovskite interface and acts as an efficient hole transport layer (HTL), while TiO 2 passivates surface defects and extracts photogenerated electrons. 90 The optimized device exhibited an ultralow dark current of ∼10 −11 A, rise/fall times of 0.056/0.25 ms, LDR = 186.7 dB, and an ultralow detection limit of 857 pW cm −2 . Fernandez-Izquierdo et al 91 applied an innovative close space sublimation (CSS) process to deposit thin CsPbBr 3 films with controlled thickness.…”

“…Ji et al fabricated an all-inorganic NiO x /CsPbBr 3 /TiO 2 photodetector, where the perovskite layer was formed by spin-coating and the two charge transport layers were formed via atomic layer deposition. The NiO x layer assists in forming a high-quality perovskite layer via an efficient interfacial interaction at the substrate/perovskite interface and acts as an efficient hole transport layer (HTL), while TiO 2 passivates surface defects and extracts photogenerated electrons . The optimized device exhibited an ultralow dark current of ∼10 –11 A, rise/fall times of 0.056/0.25 ms, LDR = 186.7 dB, and an ultralow detection limit of 857 pW cm –2 .…”

All‐Inorganic Cesium‐Based Hybrid Perovskites for Efficient and Stable Solar Cells and Modules

“…In addition, it is worth noticing that all-inorganic single junction devices offer interesting potential applications in high impact optoelectronics. Examples include photodetectors for gamma and X-rays detection, [107][108][109][110][111] scintillators, [112][113][114][115] photocatalysts, [116][117][118][119] and light emitting devices, [120][121][122][123] offering a plethora of new attractive solutions.…”