Cesium Lead Halide Nanocrystals based Flexible X‐Ray Imaging Screen and Visible Dose Rate Indication on Paper Substrate

Chen, Huanyu; Wang, Qian; Peng, Guoqiang; Wang, Shuo; Lei, Yutian; Wang, Haoxu; Yang, Zhou; Sun, Jie; Li, Nan; Zhao, Lei; Lan, Wei; Jin, Zhiwen

doi:10.1002/adom.202102790

Cited by 51 publications

(47 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides, the high PLQY of TADF effectively ensures the light out-coupling efficiency, enabling a high scintillation light yield. Generally, for the all-inorganic semiconductor scintillators, such as CsPbBr 3 and CdTe, [7,[46][47][48] there is a conflict between large Stokes shift and high luminescence efficiency. While, in the Cs 2 ZrCl 6 scintillators with TADF nature, both two desirable properties can be taken into account simultaneously.…”

Section: Resultsmentioning

confidence: 99%

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

et al. 2022

View full text Add to dashboard Cite

Flexible scintillator screens with environmental stability, high sensitivity, and low cost have emerged as candidates for X‐ray imaging applications. Here, a large‐scale and cost‐efficient solution synthesis of the vacancy‐ordered double perovskite Cs2ZrCl6, which is characterized by thermal activation delayed fluorescence (TADF) dominated by triplet emission under X‐ray irradiation, is demonstrated. The large Stokes shift and efficient luminescence collection of TADF effectively ensure the light outcoupling efficiency. Further, flexible X‐ray scintillator screens with an area of 400 cm2 are prepared using poly(dimethylsiloxane) (PDMS) as the carrier, exhibiting excellent scintillation properties with light yields as high as 49 400 photons MeV−1, spatial resolutions up to 18 lp mm−1 and detection limits as low as 65 nGy s−1. Finally, the high‐quality imaging results of non‐planar and dynamic objects by such screens are demonstrated. It is believed that the explored Cs2ZrCl6@PDMS flexible scintillator screens would offer a big step toward expanding the application range of scintillators in different environments.

show abstract

Section: Resultsmentioning

confidence: 99%

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Moreover, a high X-ray imaging resolution of 18.3 lp mm -1 can be achieved, exceeding all the reported organic and most conventional inorganic scintillators. 10,[34][35][36][37][38][39] These findings provide a powerful design approach and promising new alternative materials for fabricating organic X-ray imaging scintillators with outstanding sensitivity, low cost, and high stability using a simple molecular engineering strategy involving TADF chromophores. TADF-H was selected as the preferred TADF system due to its large HOMO-LUMO separation, which largely minimizes the impact of heavy atoms on its TADF performance.…”

Section: Introductionmentioning

confidence: 92%

Heavy-atom engineering of thermally activated delayed fluorophores for high-performance X-ray imaging scintillators

et al. 2022

View full text Add to dashboard Cite

The architectural design and fabrication of low-cost and reliable organic X-ray imaging scintillators with high light yield, ultralow detection limits, and excellent imaging resolution is becoming one of the most attractive research directions for chemists, materials scientists, physicists, and engineers due to the devices' promising scientific and applied technological implications. However, the optimal balance between the X-ray absorption capability, exciton utilization efficiency, and photoluminescence quantum yield (PLQY) of organic scintillation materials is extremely difficult to achieve because of several competitive nonradiative processes, including intersystem crossing and internal conversion. Here, we introduced heavy atoms (Cl, Br, I) into thermally activated delayed fluorescence (TADF) chromophores to significantly increase their X-ray absorption cross-section while maintaining their unique TADF properties and high PLQY. Most importantly, the X-ray imaging screens fabricated using TADF-Br chromophores exhibited a relative light yield of approximately 20,000 photons/MeV, which is comparable with some inorganic scintillators. In addition, the detection limit of 64.5 nGy s -1 is several times lower than the standard dosage for X-ray diagnostics, demonstrating its high potential in medical radiography. Moreover, a high X-ray imaging resolution of 18.3 line pairs (lp) mm -1 was successfully achieved, exceeding the resolution of all the reported organic scintillators and most conventional inorganic scintillators. This study could help revive research on organic X-ray imaging scintillators and pave the way toward exciting applications for radiology and security screening.

show abstract

“…It can also be observed that the E g of CsPbCl 3 QDs is larger than CsPbBr 3 QDs in absorption spectra. [39] For the QDs layer, we further explore the effect on morphology of the CsPbI 3 film. The surface of CsPbI 3 film after annealing is nonuniform and contains many small pinholes, which can cause serious charge recombination.…”

Section: Resultsmentioning

confidence: 99%

Double‐Layer Quantum Dots as Interfacial Layer to Enhance the Performance of CsPbI₃ Solar Cells

Zhang

Chen

et al. 2022

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

their attention to the cesium-based inorganic perovskite of CsPbX 3 (X = Cl, Br, and I), which possess favorable thermal endurance, and component stability. [12] Among these CsPbX 3 , the representative CsPbI 3 light-absorbing material has become a research hotspot for its suitable band gap (E g ) and high absorption coefficient. [13] However, the relatively high defect density and nonradiative recombination are still primarily obstacles to improve CsPbI 3 PSCs performance. [14] Meanwhile, surface and interfacial defects on film can create ion migration channels to accelerate degradation of CsPbI 3 PSCs. [15] Therefore, reducing its defect density, suppressing nonradiative recombination, and enhancing stability are of great significance to improve the device performance.Previous studies have shown that energy band mismatch produces nonradiative recombination at perovskite film/transport layer interface. [16] Meanwhile, there are also many defects on film surface, especially at grain boundaries (GBs), which can cause charge recombination. [17] All of this causes a lot of energy loss. Interface engineering is an efficient and reliable strategy, which mainly through interface modification, adding buffer layers, dopant and so on to optimize interfacial contact and film morphology. [18][19][20] Appropriate interface engineering not only can achieve energy level alignment, but also passivate surface defects, which greatly improves the PCE of PSCs. [21,22] For instance, Xu et al. introduced the (CsPbI 2 Br) 1−x (CsPbI 3 ) x layer as intercalation layer between CsPbI 2 Br film and hole transport layer (HTL) to minimize the energy loss, resulting in good crystalline quality and energy level alignment. [23] Tian and co-workers employed cathode interlayer and anode interlayer to tune the work function of SnO 2 and improve the crystallinity of CsPbI 2 Br film with larger grain size. The interaction of these interlayers can also passivate surface trap states of CsPbI 2 Br film. [24] These works directly demonstrate the feasibility of interface engineering.Currently, inorganic perovskite colloidal quantum dots (QDs) are widely used in interface engineering due to their unique features such as tunable energy levels, low excitation energies, excellent ambient stability and so on. [25][26][27] These merits show huge application prospects as interface modifiers. [28] According to previous reports, incorporation of QDs can passivate defects and tune surface morphology of perovskite film, thus retarding carrier recombination. [29][30][31] Through the insertion of QDs layer, CsPbI 3 has drawn constant interest in the field of perovskite solar cells (PSCs), due to its remarkable photovoltaic performance and thermal stability. Nonetheless, further development of CsPbI 3 PSCs requires solving larger energy loss problem, which is primarily caused by charge recombination and energy band mismatch at the interface. Here, a double-layer interface engineering concept is introduced that uses CsPbBr 3 and CsPbCl 3 colloidal quantum dots (QDs) t...

show abstract

Cesium Lead Halide Nanocrystals based Flexible X‐Ray Imaging Screen and Visible Dose Rate Indication on Paper Substrate

Cited by 51 publications

References 48 publications

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

Heavy-atom engineering of thermally activated delayed fluorophores for high-performance X-ray imaging scintillators

Double‐Layer Quantum Dots as Interfacial Layer to Enhance the Performance of CsPbI₃ Solar Cells

Contact Info

Product

Resources

About

Cesium Lead Halide Nanocrystals based Flexible X‐Ray Imaging Screen and Visible Dose Rate Indication on Paper Substrate

Cited by 51 publications

References 48 publications

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

Thermally Activated Delayed Fluorescence Zirconium‐Based Perovskites for Large‐Area and Ultraflexible X‐ray Scintillator Screens

Heavy-atom engineering of thermally activated delayed fluorophores for high-performance X-ray imaging scintillators

Double‐Layer Quantum Dots as Interfacial Layer to Enhance the Performance of CsPbI3 Solar Cells

Contact Info

Product

Resources

About

Double‐Layer Quantum Dots as Interfacial Layer to Enhance the Performance of CsPbI₃ Solar Cells