Flexible Lead-Free X-ray Detector from Metal–Organic Frameworks

Abstract

Semiconductive metal–organic frameworks (MOFs) obtained by specific host–guest interactions have attracted a large interest in the last two decades, promising development of next-generation electronic devices. Herein, we designed and presented flexible X-ray detectors using Ni-DABDT (DABDT = 2,5-diamino-1,4-benzenedithiol dihydrochloride) MOFs as the absorbing layer. The π–d coupling interactions of Ni-DABDT throughout the framework implement a conspicuous carrier transportation pathway. The detector that converts X-ray photons directly into carriers manifests an attractive achievement with high detection sensitivity of 98.6 μC Gyair –1 cm–2, with a low detection limit of 7.2 μGyair s–1 for the radiation robustness. This work provides insights for next-generation green and high-performance flexible sensor detectors by utilizing MOF materials with the benefits of a designable structure and tunable property, demonstrating a proof-of-concept in wearable X-ray detectors for radiation monitoring and imaging.

Boosting the Optoelectronic Performance by Regulating Exciton Behaviors in a Porous Semiconductive Metal–Organic Framework

“…The μτ product can be derived from the bias-dependent photocurrent curve by employing the modified Hecht equation where L is the thickness of the material, I 0 is the saturated photoinduced signal current, and V is the applied bias. A μτ product of 1.12 × 10 –3 cm 2 V –1 of the RhB + @TbTATAB device was obtained (Figure b), which is comparable to those of perovskite single crystals (Table S2) such as Cs 2 AgBiBr 6 (3.75 × 10 –3 cm 2 V –1 ) and (BA) 2 CsAgBiBr 7 (1.21 × 10 –3 cm 2 V –1 ) and many times higher than that of the MAPbI 3 wafers (2 × 10 –4 cm 2 V –1 ) . Importantly, this high μτ product represents the record value for the MOF-based X-ray detectors. , The meliorative exciton behavior from the host–guest interaction gave rise to a 3 times increase in the μτ product while the figure of the TbTATAB device is only 3.21 × 10 –4 cm 2 V –1 .…”

Metal‐Free PAZE‐NH4X3⋅H2O Perovskite for Flexible Transparent X‐ray Detection and Imaging

“…The comparison of sensitivity in flexible X‐ray detectors with different kinds of semiconductors, including metal‐free, organic and metal‐containing (with or without Pb), are summarized in Figure 3i and Table S3. Notably, the sensitivity in this work exceeds most works of two‐dimensional based MHP detector (PEA 2 PbBr 3 , 806 μC Gy air −1 cm −2 ) and all‐inorganic MHP (CsPbBr 3 , 1450 μC Gy air −1 cm −2 ), which is comparable to the most advanced Pb‐based MHP detectors (MAPb(I 0.9 Cl 0.1 ) 3 , 8696±228 μC Gy air −1 cm −2 ) under low electric field [46–52] …”

“…Notably, the sensitivity in this work exceeds most works of two-dimensional based MHP detector (PEA 2 PbBr 3 , 806 μC Gy air À 1 cm À 2 ) and all-inorganic MHP (CsPbBr 3 , 1450 μC Gy air À 1 cm À 2 ), which is comparable to the most advanced Pb-based MHP detectors (MAPb(I 0.9 Cl 0.1 ) 3 , 8696 � 228 μC Gy air À 1 cm À 2 ) under low electric field. [46][47][48][49][50][51][52] Subsequently, the mechanical flexibility and stability of the device were further explored with different bending cycles (0-2500 cycles) and bending radii (∞, 9.93, 8.94, 7.83 and 5.92 mm). The R C defines as the different radii of bending curvatures, and one cycle defines as that the film is bent from the flat state to a certain bending radius and recovers to the initial state, as shown in Figure 4a.…”

Molecular Doping of Flexible Lead‐Free Perovskite‐Polymer Thick Membranes for High‐Performance X‐Ray Detection

“…[17,18] The excellent sensitivity achieved by these flexible MA 3 Bi 2 I 9 devices highlights the importance of charge transport engineering for polycrystalline films. We also compared the sensitivity values achieved by environmentally friendly flexible X-ray detectors based on lead-free semiconductors, such as (Poly)-Cs 2 AgBiBr 6 , [19] polymerencapsulated Cs 2 TeI 6 , [40] TIPS-pentacence, [41] PDMS : Bi 2 O 3 , [42] P3HT : Bi 2 O 3 , [43] Ni-DABDT MOFs (Ni-DABDT), [44] MOF (SCU-13), [45] SWNT, [46] and Ga 2 O 3 . [47] The sensitivity units have been converted into μC Gy air À 1 cm À 2 for comparison (Figure 4f).…”