Cherusseri Jayesh, Varma Sreekanth J, Pradhan Basudev, Li Jinxin, Kumar Jitesh, Barrios Elizabeth, Amin Mohammed Zain, Towers Andrew, Gesquiere Andre, Thomas Jayan
NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA.
Nanoscale. 2020 May 14;12(18):10072-10081. doi: 10.1039/c9nr10543c.
We present a simple and facile method to synthesize nanoplatelets of 2D Ruddlesden-Popper (RP) perovskites of the type (CH3(CH2)3NH3)2(CH3NH3)Pb2I7 where n = 2. The 2D RP nanoplatelets are synthesized from bulk 2D RP crystals via a reflux pre-treatment mediated-ultrasonication method. The as-synthesized 2D RP nanoplatelets are highly air-stable even after two months of storage under an ambient atmosphere. The bulk 2D RP crystals and 2D RP nanoplatelets are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Kelvin probe force microscopy, UV-visible spectroscopy, X-ray photoelectron spectroscopy (XPS), photoluminescence, time correlated single photon counting measurement, etc. A significant blue shift in the ultraviolet-visible absorption spectrum, high photoluminescence in the UV region, and the modified work function of the nanoplatelets indicate a strong quantum confinement effect. The quantum confinement in the nanoplatelets is further confirmed using XPS. A photodetector fabricated using these 2D RP nanoplatelets exhibits a high photodetectivity of 3.09 × 1010 Jones.
我们展示了一种简单易行的方法来合成二维Ruddlesden-Popper（RP）钙钛矿（CH3(CH2)3NH3）2(CH3NH3)Pb2I7（其中n = 2）的纳米片。二维RP纳米片是通过回流预处理介导的超声法从块状二维RP晶体合成的。所合成的二维RP纳米片即使在环境大气中储存两个月后仍具有高度的空气稳定性。使用X射线衍射、扫描电子显微镜、透射电子显微镜、开尔文探针力显微镜、紫外可见光谱、X射线光电子能谱（XPS）、光致发光、时间相关单光子计数测量等对块状二维RP晶体和二维RP纳米片进行了表征。紫外可见吸收光谱中的显著蓝移、紫外区域的高光致发光以及纳米片的功函数改变表明存在强烈的量子限域效应。使用XPS进一步证实了纳米片中的量子限域效应。使用这些二维RP纳米片制造的光电探测器表现出3.09×1010琼斯的高光探测率。
