One-Dimensional orthorhombic CsPbI3 polycrystalline thick film for efficient and highly stable direct X-ray detection and imaging

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 486; p. 150394
• Main Authors: Wang, Xinyu, Li, Hongkun, Xue, Zhiyu, Xiang, Yong, Hu, Xiaoran, Li, Zhenlin, Qin, Haiqing, Qin, Aimiao, Zhang, Hetong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2024
• Subjects: Liquid epitaxy; Orthorhombic CsPbI3; Polycrystalline thick film; X-ray detector; X-ray detector; Orthorhombic CsPbI3; Polycrystalline thick film; Liquid epitaxy
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2024.150394

•Liquid epitaxy boosts δ-CsPbI3's one-dimensional growth, enhancing carrier transition.•Sensitivity reaches 1768.46 μC Gyair-1 cm−2 at 432 V mm−1, outperforming α-Se and single crystalline δ-CsPbI3 detectors.•Retains 91.34 % sensitivity after 7 days in air, showcasing impressive long-term stability.•Successful integration with a thin-film transistor array for 8-bit imaging in a 64 × 64 matrix.•Opens the door for commercial high-performance direct X-ray detectors, solving the "absorption vs. transportation" issue. An ideal direct X-ray detector should convert a low dose of X-ray photons into large quantity of electrical signals, coupled with sustained long-term stability. Nevertheless, a notable conflict arises between X-ray absorption efficiency and carrier transport in thick polycrystalline perovskite films. Moreover, conventional perovskite materials exhibit inherent challenges regarding the stability of their crystal phase and the consistency of the photocurrent. To circumvent these limitations, a polycrystalline perovskite thick film is proposed using orthorhombic CsPbI3 (δ-CsPbI3) as a highly stable active material. Combined with the liquid epitaxy process, δ-CsPbI3 prefers one-dimensional growth along the carrier transportation direction, which suppresses the formation of grain boundaries, enabling high carrier mobility while maintaining X-ray absorption for a thick polycrystalline film. Consequently, the polycrystalline δ-CsPbI3 based detector exhibits a highest sensitivity of 1768.46 μC Gyair-1 cm−2 at an electric field of 432 V mm−1 which is 88.42-fold higher than α-Se based detectors and 190-fold higher than the single crystalline δ-CsPbI3 based detector, respectively. The sensitivity maintains 91.34 % of its initial state after 7 days exposure in the air. Combing with a thin-film transistor array, the detector achieves 8-bit imaging within a 64 × 64 matrix. This work provides a feasible method for commercialized production of high-performance direct X-ray detectors.