Tan Zhaozhong, Jung Uijin, Jeong Seongmin, Park Jinsub
Department of Electronic Engineering, Hanyang University, Seoul 04763, Korea.
Department of Semiconductor Engineering, Hanyang University, Seoul 04763, Korea.
ACS Appl Mater Interfaces. 2024 Aug 28;16(34):45147-45155. doi: 10.1021/acsami.4c07059. Epub 2024 Aug 13.
In this study, we propose large-scale CsPbBr (CPB) single-crystalline films (SCFs) grown by a one-step vapor-phase epitaxy (VPE) method for application in optoelectronic devices. After optimizing the transport speed of the precursor and cooling rate, we obtained continuous CPB films with a lateral size exceeding 2 cm, and the thickness could be controlled from several micrometers to hundreds of nanometers. Crystallography and optoelectronic characterization proved the excellent crystallinity and very low trap density (2.14 × 10) of the SCFs. Furthermore, we demonstrate a transfer-assembly strategy for fabricating perovskite SCF-based heterostructures for visible photodetectors. The high-quality SCF films in the active layer suppress the leakage current, leading to a low dark current of 5 × 10 A at -0.6 V. Therefore, the self-biased photodetector based on the vertical CsPbBr SCF-SnO heterostructure showed a high responsivity of 1.9 A/W, a detectivity of 4.65 × 10 Jones, and a large on/off ratio of 4.63 × 10 under a 1 mW/cm 450 nm light illumination. Our study not only demonstrates the excellent performance of single-crystalline perovskite-based photodiodes but also provides a universal assembly method for the integration of monocrystalline perovskite films in optoelectronic devices.
在本研究中，我们提出了一种通过一步气相外延（VPE）方法生长的用于光电器件的大规模CsPbBr（CPB）单晶薄膜（SCF）。在优化前驱体的传输速度和冷却速率后，我们获得了横向尺寸超过2 cm的连续CPB薄膜，其厚度可从几微米控制到几百纳米。晶体学和光电特性证明了SCF具有优异的结晶度和非常低的陷阱密度（2.14×10）。此外，我们展示了一种用于制造基于钙钛矿SCF的可见光探测器异质结构的转移组装策略。有源层中的高质量SCF薄膜抑制了漏电流，在-0.6 V时导致低暗电流为5×10 A。因此，基于垂直CsPbBr SCF-SnO异质结构的自偏置光电探测器在1 mW/cm 450 nm光照下显示出1.9 A/W的高响应度、4.65×10 Jones的探测率和4.63×10的大开关比。我们的研究不仅证明了基于单晶钙钛矿的光电二极管的优异性能，还为单晶钙钛矿薄膜在光电器件中的集成提供了一种通用的组装方法。
