PL谱简介.pptx

Group Report 2017/03/13 讲述有关PL谱的问题 目录 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。 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。 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/ CH3NH3PbI3 /C has stronger absorption from 600 to 800nm than that of glass/ CH3NH3PbI3, 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. CH3NH3PbI3 and CH3NH3PbI3/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。 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 MAPbI3-0.2prefilm is largely reduced compared to that of theMAPbI3-0prefilm, demonstrating an enhanced charge carrier extraction and reduced recombination. The thickness reduction of perovskite film and lower amount of residual PbI2 before mentioned may lead to the decreased intensity of PL spectra. The poor performance of MAPbI3-0.4prefilm 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 Thank You!