TY - JOUR
T1 - Morphology of X-ray detector Cs2TeI6 perovskite thick films grown by electrospray method
AU - Guo, Jun
AU - Xu, Yadong
AU - Yang, Wenhui
AU - Zhang, Binbin
AU - Dong, Jiangpeng
AU - Jie, Wanqi
AU - Kanatzidis, Mercouri G.
N1 - Funding Information:
We would like to acknowledge the financial support from the National Natural Science Foundations of China (No. 51872228 and U1631116). The project was also supported by the National Key Research and Development Program of China (2016YFE0115200), the Natural Science Basic Research Plan in Shaanxi Province of China (2019ZDLGY04-07), and the Fundamental Research Funds for the Central Universities (3102017zy057 and 3102018jcc036). At Northwestern University, this work was supported by the Department of Homeland Security ARI program with grant 2014-DN-077-ARI086-01.
Publisher Copyright:
© The Royal Society of Chemistry 2019.
PY - 2019
Y1 - 2019
N2 - For the purpose of developing Cs2TeI6 based X-ray detectors and imaging devices, Cs2TeI6 thick films were prepared using the electrospray method under ambient conditions. The effects of spraying parameters on the morphology of the films were investigated. During the electrospray process, we observed that Cs2TeI6 microdroplets changed to a steady cone jet and then to an unstable multi-jet model as the electrical bias increased from 6 kV to 12 kV, resulting in variable film morphologies. Five representative solvent systems with different evaporation rates and contact angles on the FTO/double-TiO2 substrates were studied. We find a strong correlation of the contact angle with the speed of primary nucleation, growth mode and subsequent film morphology. Moreover, the crystalline quality has been improved with the rise of substrate temperature. Finally, a dense and uniform Cs2TeI6 film was obtained with an electrical bias of 10 kV using dimethyl formamide (DMF) as the solvent at a substrate temperature of 160 °C. The resulting Cs2TeI6 films have resistivity on the order of 1010 Ω cm, which indicates potential applications in X-ray detection and imaging. The films show a strong photoresponse to visible light based on the Cs2TeI6 thick film devices, and an on-off ratio of 22 under 425 nm light (∼65 mW cm-2). The sensitivity of the assembled Cs2TeI6 perovskite-based detectors can be 2.4 nC R-1 cm-2 under illumination of 60 kVp X-rays.
AB - For the purpose of developing Cs2TeI6 based X-ray detectors and imaging devices, Cs2TeI6 thick films were prepared using the electrospray method under ambient conditions. The effects of spraying parameters on the morphology of the films were investigated. During the electrospray process, we observed that Cs2TeI6 microdroplets changed to a steady cone jet and then to an unstable multi-jet model as the electrical bias increased from 6 kV to 12 kV, resulting in variable film morphologies. Five representative solvent systems with different evaporation rates and contact angles on the FTO/double-TiO2 substrates were studied. We find a strong correlation of the contact angle with the speed of primary nucleation, growth mode and subsequent film morphology. Moreover, the crystalline quality has been improved with the rise of substrate temperature. Finally, a dense and uniform Cs2TeI6 film was obtained with an electrical bias of 10 kV using dimethyl formamide (DMF) as the solvent at a substrate temperature of 160 °C. The resulting Cs2TeI6 films have resistivity on the order of 1010 Ω cm, which indicates potential applications in X-ray detection and imaging. The films show a strong photoresponse to visible light based on the Cs2TeI6 thick film devices, and an on-off ratio of 22 under 425 nm light (∼65 mW cm-2). The sensitivity of the assembled Cs2TeI6 perovskite-based detectors can be 2.4 nC R-1 cm-2 under illumination of 60 kVp X-rays.
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U2 - 10.1039/c9tc02022e
DO - 10.1039/c9tc02022e
M3 - Article
AN - SCOPUS:85069792539
VL - 7
SP - 8712
EP - 8719
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 28
ER -