Zhang Hongbin, Chen Hui, Stoumpos Constantinos C, Ren Jing, Hou Qinzhi, Li Xin, Li Jiaqi, He Hongcai, Lin Hong, Wang Jinshu, Hao Feng, Kanatzidis Mercouri G
School of Materials and Energy , University of Electronic Science and Technology of China , Chengdu 610054 , China.
Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States.
ACS Appl Mater Interfaces. 2018 Dec 12;10(49):42436-42443. doi: 10.1021/acsami.8b16124. Epub 2018 Nov 30.
The quality of perovskite films is a crucial factor governing the photovoltaic performance of perovskite solar cells. However, perovskite films fabricated by the conventional one-step spin-coating procedure are far from ideal due to uncontrollable crystal growth. Herein, we report a facile recrystallization procedure using a thiazole additive coupled with vapor annealing to simultaneously modulate the perovskite crystal growth and suppress the surface defects. High quality perovskite films with no pin holes, high crystallinity, large grain size, and low roughness were obtained. Moreover, using the space charge limited current method, we observe that the defect density of the as-prepared perovskite films with the thiazole additive was decreased by 40% when compared with the film without thiazole. The lower defect density of these perovskite films enables the achievement of a final power conversion efficiency of 18% and an exceptionally high fill factor of 0.82, which correspond to a 25% enhancement compared with the control device. Our results reveal a novel and facile path to modulate the perovskite crystal growth and simultaneously suppress the film defect density and increasing efficiency in perovskite photovoltaics and related optoelectronic applications.
钙钛矿薄膜的质量是决定钙钛矿太阳能电池光伏性能的关键因素。然而，由于晶体生长不可控，通过传统的一步旋涂工艺制备的钙钛矿薄膜远非理想状态。在此，我们报道了一种简便的重结晶工艺，该工艺使用噻唑添加剂并结合气相退火，以同时调节钙钛矿晶体生长并抑制表面缺陷。获得了无针孔、高结晶度、大晶粒尺寸和低粗糙度的高质量钙钛矿薄膜。此外，使用空间电荷限制电流方法，我们观察到与不含噻唑的薄膜相比，添加噻唑添加剂的制备态钙钛矿薄膜的缺陷密度降低了40%。这些钙钛矿薄膜较低的缺陷密度使得最终功率转换效率达到18%，填充因子高达0.82，与对照器件相比提高了25%。我们的结果揭示了一条新颖且简便的途径，可用于调节钙钛矿晶体生长，同时抑制薄膜缺陷密度，并提高钙钛矿光伏及相关光电器件的效率。
