PL谱简介.ppt

,2021/10/10,Company Logo,*,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,单击此处编辑母版标题样式,GroupReport,2017/03/13,2021/10/10,1,讲述有关,PL,谱的问题,目录,2021/10/10,2,讲述有关,PL,谱的问题,基本原理是,：半导体材料受到光的激发时，电子产生由低能级向高能级的跃迁，产生电子,-,空穴对，形成非平衡载流子。,这种处于激发态的电子在半导体中运动一段时间后，又回复到较低的能量状态，并发生电子,-,空穴对的复合。非平衡电子可以直接越过禁带与价带空穴复合，也可以在被禁带中的定域态俘获后再与空穴复合。复合可以是辐射复合即发光，或者非辐射的表面复合、俄歇复合和发射多声子的复合。,复合过程中，电子,-,空穴对如果以光的形式释放出多余的能量就称为,光致发光,。,2021/10/10,3,Contents,光致发光谱,发射光谱：,PL,激发光谱：,PLE,固定发射光的波长，改变激发光的波长，记录荧光强度随激发波长的变化。,固定激发光的波长，改变不同发射波长，记录荧光强度随发射波长的变化。,图为同一物质的吸收光谱（,UV-Vis,）、荧光激发光谱（,PLE,）和荧光发射光谱图（,PL,）,吸收光谱的纵坐标是吸光度（,Absorbance,），反应物质吸收光的情况；荧光光谱的纵坐标是分子发出的荧光强度（,Intensity,），其不仅与物质吸光能力有关还和量子效率有关。,2021/10/10,4,Contents,实例,1,：低温碳层做电极的,PL,谱,目的：为了检测碳层在电池中是否能收集空穴,Although the sample of glass/CH,3,NH,3,PbI,3,/C has stronger absorption from 600 to 800nm than that of glass/CH,3,NH,3,PbI,3,a carbon electrode quenches the perovskite steady-state PL.,Conclusion,：,First,it is used as a hole acceptor.Second,it works as a conductive electrode to transport holes to the external circuit.,CH,3,NH,3,PbI,3,and CH,3,NH,3,PbI,3,/C on glass substrate,AT007;AT009,photoluminescence(PL)quenching,结论：,photoluminescence(PL)quenching,可以表征,碳层对钙钛矿层中电荷的提取，通过,PL,强度反应出,来。,2021/10/10,5,Contents,实例,2,：,as-prepared film before sequential spin-coating,目的：为了研究光生电子的复合,steady-state photoluminescence(PL)measurement,The perovskite PL quantum yield of the MAPbI,3,-0.2prefilm is largely reduced compared to that of theMAPbI,3,-0prefilm,demonstrating an enhanced charge carrier extraction and reduced recombination.,The thickness reduction of perovskite film and lower amount of residual PbI,2,before mentioned may lead to the decreased intensity of PL spectra.,The poor performance of MAPbI,3,-0.4prefilm is proved by the PL curve,where an intensively sharp peak appears at 770 nm.The high recombination is ascribed from the low coverage of perovskite film.,结论：,PL,谱可以表征位于介孔层内钙钛矿层的载流子复合以及氧化钛对不同钙钛矿,层中载流子的提取能力。通过,PL,强度反应出来。,Jiang,2021/10/10,6,Thank You!,2021/10/10,7,