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

详细信息    查看全文

• 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 CH₃NH₃PbI₃ (MAPbI₃)/MoO₃ 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 MAPbI₃ and MoO₃, 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 MAPbI₃/NPB/MoO₃ interface facilitates the hole transportation from the MAPbI₃ layer through the NPB layer toward the NPB/MoO₃ 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 MoO₃ and the HOMO of NPB. Therefore, the modification by the ultrathin NPB interlayer on the electronic structures of the MAPbI₃/MoO₃ interface can greatly improve the hole extraction and thus enhance the power efficiency of the corresponding solar cells.