Wang Wen, Zhang Zongbao, Cai Yangyang, Chen Jinshan, Wang Jianming, Huang Riyan, Lu Xubing, Gao Xingsen, Shui Lingling, Wu Sujuan, Liu Jun-Ming
Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou, 510006, China.
South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China.
Nanoscale Res Lett. 2016 Dec;11(1):316. doi: 10.1186/s11671-016-1540-4. Epub 2016 Jun 29.
In this work, perovskite solar cells (PSCs) with CH3NH3PbI3-x Cl x as active layer and spiro-OMeTAD as hole-transport media have been fabricated by one-step method. The methylammonium iodide (CH3NH3I) solution with different concentrations is used to modify the interface between mesoporous TiO2 (meso-TiO2) film and CH3NH3PbI3-x Cl x perovskite layer. Several techniques including X-ray diffraction, scanning electron microscopy, optical absorption, electrochemical impedance spectroscopy (EIS) and photoluminescence are used to investigate the effect of the interfacial modification. It is found that the interfacial modification by CH3NH3I enhance the crystallinity and increase the grain size of CH3NH3PbI3-x Cl x layer, and improve the surface wetting properties of perovskite precursor on meso-TiO2 film. The sunlight absorption and external quantum efficiency of PSCs in the visible region with wavelength less than 600 nm have been improved. The Nyquist plots obtained from the EIS suggest that the CH3NH3I modification can reduce the charge recombination rates. The photoluminescence measurement shows that the exciton dissociation in the modified devices is more effective than that in the control samples. The photovoltaic performance of the modified devices can be significantly improved with respect to the reference (control) devices. The CH3NH3I modified devices at the optimized concentration demonstrate the average power conversion efficiency of 12.27 % in comparison with the average efficiency of 9.68 % for the reference devices.
在这项工作中，采用一步法制备了以CH3NH3PbI3-x Cl x为活性层、螺环-OMeTAD为空穴传输介质的钙钛矿太阳能电池（PSC）。使用不同浓度的甲基碘化铵（CH3NH3I）溶液来修饰介孔TiO2（介孔-TiO2）薄膜与CH3NH3PbI3-x Cl x钙钛矿层之间的界面。采用包括X射线衍射、扫描电子显微镜、光吸收、电化学阻抗谱（EIS）和光致发光在内的多种技术来研究界面修饰的效果。研究发现，CH3NH3I进行的界面修饰提高了CH3NH3PbI3-x Cl x层的结晶度并增大了晶粒尺寸，改善了钙钛矿前驱体在介孔-TiO2薄膜上的表面润湿性。提高了波长小于600 nm的可见光区域内PSC的太阳光吸收和外量子效率。从EIS获得的奈奎斯特图表明，CH3NH3I修饰可以降低电荷复合率。光致发光测量表明，修饰器件中的激子解离比对照样品更有效。相对于参考（对照）器件，修饰器件的光伏性能可以得到显著改善。在优化浓度下，CH3NH3I修饰的器件的平均功率转换效率为12.27%，而参考器件的平均效率为9.68%。
