Nano-Sensors and Detectors Lab., and Nano Plasmo-Photonic Research Group, Faculty of Electrical and Computer Engineering, Tarbiat Modares University, Tehran, Iran.
Sci Rep. 2023 May 24;13(1):8374. doi: 10.1038/s41598-023-35546-1.
Here, we achieved pinhole-free 2D Ruddlesden-Popper Perovskite (RPP) BAPbI layers with close packed crystalline grains with dimension of about 30 × 30 µm, which have been demonstrated to be favorable for optoelectronic applications, such as fast response RPP-based metal/semiconductor/metal photodetectors. We explored affecting parameters in hot casting of BAPbI layers, and proved that oxygen plasma treatment prior to hot casting plays a significant role to achieve high quality close packed polycrystalline RPP layers at lower hot cast temperatures. Moreover, we demonstrate that crystal growth of 2D BAPbI can be dominantly controlled by the rate of solvent evaporation through substrate temperature or rotational speed, while molarity of the prepared RPP/DMF precursor is the dominant factor that determines the RPP layer thickness, and can affect the spectral response of the realized photodetector. Benefiting from the high light absorption and inherent chemical stability of 2D RPP layers, we achieved high responsivity and stability, and fast response photodetection from perovskite active layer. We achieved a fast photoresponse with rise and fall times of 189 µs and 300 µs, and the maximum responsivity of 119 mA/W and detectivity of 2.15 × 10 Jones in response to illumination wavelength of 450 nm. The presented polycrystalline RPP-based photodetector benefits from a simple and low-cost fabrication process, suitable for large area production on glass substrate, a good stability and responsivity, and a promising fast photoresponse, even around that of exfoliated single crystal RPP-based counterparts. However, it is well known that exfoliation methods suffer from poor repeatability and scalability, which make them incompatible with mass production and large area applications.
在这里，我们实现了无针孔的二维 Ruddlesden-Popper 钙钛矿（RPP）BAPbI 层，其具有约 30×30 µm 的紧密堆积的结晶颗粒，这有利于光电应用，例如基于 RPP 的快速响应金属/半导体/金属光电探测器。我们探索了在 BAPbI 层热铸中的影响参数，并证明在热铸之前进行氧等离子体处理对于在较低的热铸温度下获得高质量的紧密堆积多晶 RPP 层起着重要作用。此外，我们证明二维 BAPbI 的晶体生长可以通过衬底温度或旋转速度控制溶剂蒸发的速率来主导，而制备的 RPP/DMF 前体的摩尔浓度是决定 RPP 层厚度的主要因素，并会影响实现的光电探测器的光谱响应。得益于二维 RPP 层的高光吸收和固有化学稳定性，我们实现了高响应度和稳定性，以及来自钙钛矿活性层的快速光探测。我们实现了快速光响应，上升和下降时间分别为 189 µs 和 300 µs，在 450nm 光照波长下，最大响应度为 119mA/W，探测率为 2.15×10 琼斯。所提出的基于多晶 RPP 的光电探测器受益于简单且低成本的制造工艺，适用于玻璃衬底上的大面积生产，具有良好的稳定性和响应度，以及有前途的快速光响应，甚至接近剥离单晶 RPP 基对应物的光响应。然而，众所周知，剥离方法存在重复性和可扩展性差的问题，这使得它们不适合大规模生产和大面积应用。
