MgO Nanoparticle Modified Anode for Highly Efficient SnO2-Based Planar Perovskite Solar Cells.

Junjie Ma,Guojia Fang,Hongwei Han,Cong Chen,Zhiliang Chen,Minchao Qin,Xiaolu Zheng,Xingzhong Zhao,Hongwei Lei,Guang Yang,Yaxiong Guo

doi:10.1002/advs.201700031

Abstract

Reducing the energy loss and retarding the carrier recombination at the interface are crucial to improve the performance of the perovskite solar cell (PSCs). However, little is known about the recombination mechanism at the interface of anode and SnO2 electron transfer layer (ETL). In this work, an ultrathin wide bandgap dielectric MgO nanolayer is incorporated between SnO2:F (FTO) electrode and SnO2 ETL of planar PSCs, realizing enhanced electron transporting and hole blocking properties. With the use of this electrode modifier, a power conversion efficiency of 18.23% is demonstrated, an 11% increment compared with that without MgO modifier. These improvements are attributed to the better properties of MgO‐modified FTO/SnO2 as compared to FTO/SnO2, such as smoother surface, less FTO surface defects due to MgO passivation, and suppressed electron–hole recombinations. Also, MgO nanolayer with lower valance band minimum level played a better role in hole blocking. When FTO is replaced with Sn‐doped In2O3 (ITO), a higher power conversion efficiency of 18.82% is demonstrated. As a result, the device with the MgO hole‐blocking layer exhibits a remarkable improvement of all J–V parameters. This work presents a new direction to improve the performance of the PSCs based on SnO2 ETL by transparent conductive electrode surface modification.

Highlights

Reducing the energy loss and retarding the carrier recombination at the performance and simple fabrication process.[1,2] Perovskite materials have many interface are crucial to improve the performance of the perovskite solar cell advantages such as excellent charge-car
An ultrathin wide bandgap dielectric Magnesium oxide (MgO) nanolayer is incorporated between SnO2:F (FTO) electrode and SnO2 electron transfer layer (ETL) of planar Perovskite solar cells (PSCs), realizing enhanced rier mobility, effective ambipolar charge transfer, and high optical absorption coefficient.[1g,3] Perovskite materials can be coated on the compact electron transport layer (ETL) immediately to form a planar electron transporting and hole blocking properties
Our results reveal recombination loss mechanism at anode/SnO2 interface with a n-i-p junction working mechanism and present a new direction to improve the performance of the PSCs based on SnO2 ETL by electrode surface modification using MgO as hole-blocking layer

Summary

Results and Discussion

It is conspicuous that all the photovoltaic parameters of devices have notably improved after introducing an MgO nanolayer These results proved the positive effect of MgO HBL on PSCs performance enhancement. The surface morphologies of the FTO, SnO2 ETL, and perovskite films have a significant impact on the photovoltaic performance Both scanning electron microscope (SEM) and atomic force microscopy (AFM) were employed to investigate how the additional MgO HBL influences the surface morphology and charge transportation. Thereby, it can minimize the possibility of current leakage and electron–hole recombination and improve the performance of the device. The results indicate that the MgO nanolayer can enhance the performance of the PSCs with different transparent conductive anode

Conclusion

Experimental Section

Conflict of Interest