Modification of Ultrathin NPB Interlayer on the Electronic Structures of the CH3NH3PbI3/NPB/MoO3 Interface

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• 作者：Lin Li ; Xiaoliang Liu ; Lu Lyu ; Runsheng Wu ; Peng Liu ; Yuhe Zhang ; Yuan Zhao ; Hongyang Wang ; Dongmei Niu ; Junliang Yang ; Yongli Gao
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 18, 2016
• 年：2016
• 卷：120
• 期：32
• 页码：17863-17871
• 全文大小：687K
• 年卷期：0
• ISSN：1932-7455

文摘

Modification of the ultrathin N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) insertion layer on the electronic structures of the CH<sub>3sub>NH<sub>3sub>PbI<sub>3sub> (MAPbI<sub>3sub>)/MoO<sub>3sub> interfaces is investigated using ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). It is found that when an ultrathin NPB insertion layer of 16 Å is inserted between MAPbI<sub>3sub> and MoO<sub>3sub>, the chemical reaction between the latter two can be effectively suppressed, and a favorable energy-level alignment is achieved. The valence band maximum (VBM) or highest occupied molecular orbital (HOMO) at the MAPbI<sub>3sub>/NPB/MoO<sub>3sub> interface facilitates the hole transportation from the MAPbI<sub>3sub> layer through the NPB layer toward the NPB/MoO<sub>3sub> interface. As a result, the holes can be efficiently extracted to the hole collection electrode due to the small energy offset between the conduction band minimum (CBM) of MoO<sub>3sub> and the HOMO of NPB. Therefore, the modification by the ultrathin NPB interlayer on the electronic structures of the MAPbI<sub>3sub>/MoO<sub>3sub> interface can greatly improve the hole extraction and thus enhance the power efficiency of the corresponding solar cells.