In:
Advanced Materials, Wiley
Abstract:
Conventional indirect X‐ray detectors employ scintillating phosphors to convert X‐ray photons into photodiode‐detectable visible photons, leading to low conversion efficiencies, low spatial resolutions, and optical crosstalk. Consequently, X‐ray detectors that directly convert photons into electric signals have long been desired for high‐performance medical imaging and industrial inspection. Although emerging hybrid inorganic–organic halide perovskites, such as MAPbI 3 and MAPbBr 3 , exhibit high sensitivity, they have salient drawbacks including structural instability, ion motion, and the use of toxic Pb. Here we report an ultrastable, low‐dose X‐ray detector comprising KTaO 3 perovskite films epitaxially grown on a Nb‐doped strontium titanate substrate using a low‐cost solution method. The detector exhibits a stable photocurrent under high‐dose‐irradiation, high‐temperature (200°C), and aqueous conditions. Moreover, the prototype KTaO 3 ‐film‐based detector exhibits a 150‐fold higher sensitivity (3150 μC Gy air −1 cm −2 ) and 150‐fold lower detection limit ( 〈 40 nGy air s −1 ) than those of commercial amorphous α‐Se‐based direct detectors. Systematic investigations revealed that the high stability of the detector originates from the strong covalent bonds within the KTaO 3 film, whereas the low detection limit is due to a lattice‐gradient‐driven built‐in electric field, yielding an extremely low dark current. This study unveils a new path toward the fabrication of green, stable, and low‐dose X‐ray detectors using oxide perovskite films, which have significant application potential in medical imaging and security operations. This article is protected by copyright. All rights reserved
Type of Medium:
Online Resource
ISSN:
0935-9648
,
1521-4095
DOI:
10.1002/adma.202211026
Language:
English
Publisher:
Wiley
Publication Date:
2023
detail.hit.zdb_id:
1474949-X
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