Flexible and Self‐Powered Photodetector Arrays Based on All‐Inorganic CsPbBr₃ Quantum Dots

Abstract

high-performance photodetection is highly desirable in various fields, including optical communication, imaging, and environmental monitoring. [4][5][6] Currently, GaN, Si, InGaAs, and other semiconductors have dominated the ultraviolet to near-infrared photodetection market. [7][8][9][10] These detectors are mostly assembled on rigid substrates and usually require relatively thick active materials for photonic detection, therefore, they are not compatible with flexible systems or suitable for low cost manufacturing.The demand for flexible devices has driven the research in emerging functional materials that are bendable. To date, various functional materials have been explored for constructing flexible photodetectors, such as zero-dimensional (0D) semiconductor nanostructures, 2D layered materials, and perovskites. [11][12][13][14] They can be facilely transferred to arbitrary rigid substrates and directly deposited on flexible substrates, which are favorable for flexible optoelectronics. Particularly, organometal halide perovskites (OHPs) have demon strated intriguing properties, including large absorption coefficients, tunable bandgaps, long carrier diffusion length, and high carrier mobility. [15][16][17][18][19][20] Nevertheless, their organic parts Flexible devices are garnering substantial interest owing to their potential for wearable and portable applications. Here, flexible and self-powered photodetector arrays based on all-inorganic perovskite quantum dots (QDs) are reported. CsBr/KBr-mediated CsPbBr 3 QDs possess improved surface morphology and crystallinity with reduced defect densities, in comparison with the pristine ones. Systematic material characterizations reveal enhanced carrier transport, photoluminescence efficiency, and carrier lifetime of the CsBr/KBr-mediated CsPbBr 3 QDs. Flexible photodetector arrays fabricated with an optimum CsBr/KBr treatment demonstrate a high open-circuit voltage of 1.3 V, responsivity of 10.1 A W −1 , specific detectivity of 9.35 × 10 13 Jones, and on/off ratio up to ≈10 4 . Particularly, such performance is achieved under the self-powered operation mode. Furthermore, outstanding flexibility and electrical stability with negligible degradation after 1600 bending cycles (up to 60°) are demonstrated. More importantly, the flexible detector arrays exhibit uniform photoresponse distribution, which is of much significance for practical imaging systems, and thus promotes the practical deployment of perovskite products.The "Internet of Things" (IoT) has been expected to reshape or even revolutionize human daily lives. As a fundamental technology of the IoT, flexible optoelectronics, such as solar power sources, display panels, and photodetectors, have attracted substantial research interest globally. [1][2][3] Moreover,

Floating-gate photosensitive synaptic transistors with tunable functions for neuromorphic computing

“…S2d). On the other hand, PQDs have been widely utilized to fabricate optoelectronic devices including photosensors [33], photomemories [34] and photo-sensory neurons [8] because of their excellent photosensitivity. In our case, the introduction of CsPbBr 3 PQDs is expected to provide the devices with photosensitivity, so that light can be used as another control signal to adjust the device performance.…”

Multifunctional two-dimensional glassy graphene devices for vis-NIR photodetection and volatile organic compound sensing

“…As the incident power density increased, the photocurrent became larger accordingly, due to that more photoinduced carriers were produced and collected. The power-dependent photocurrent can be fitted by the power law (I ph ∝ P β ), where β is the exponent [54]. β was determined as 0.88, as shown in Fig.…”

Recent Progress of Quantum Dot‐Based Photonic Devices and Systems: A Comprehensive Review of Materials, Devices, and Applications

“…Also, Shen et al reported all‐inorganic cesium lead bromide (CsPbBr 3 ) QD‐based photodetectors with reduced defect densities, exhibiting an enhanced photo‐responsivity of 10.1 A W −1 , a specific detectivity of 9.35 × 10 13 Jones, and a current on/off ratio up to 10 4 . [ 161 ] In particular, the cesium bromide (CsBr)/potassium bromide (KBr) treatment improved the surface morphology and the crystallinity of the film, resulting in enhanced charge transfer efficiency and lower leakage current.…”

“…In addition, flexible photodetector based on perovskite CsPbI 3 QDs with the CsBr/KBr treatment was also presented by Shen et al (Figure 12e,f). [ 161 ] The photo‐induced current retained more than 93% of original value after 60° bending and 1600 bending cycles. With high tensile strength and good stability, the flexible photodetectors ensured appropriate toughness for high photonic response and gain with great robustness against repetitive bending and stretching condition.…”