[7a-A501-1~11] 12.5 Organic solar cells

▲ [7a-A501-6] Interface Engineering of Perovskite Solar Cells using Mg-doped ZnO as Electron Selective Layers

〇(D)CHAO DING^1,6, Yaohong Zhang¹, Shuzi Hayase^2,5, Yuhei Ogomi², Taro Toyoda^1,5, Kenji Yoshino^3,5, Takashi Minemoto^4,5, Qing Shen^1,5 (1.Univ. Electro-Commun., 2.Kyushu Inst. Tech., 3.Univ. Miyazaki, 4.Ritsumeikan Univ., 5.CREST JST, 6.CSC)

Keywords:perovskite Solar Cell, interface engineering, electron selective layers

Recently, perovskite solar cell has attracted much attention as a next generation solar cell. In the solar cells, besides absorber layer material, the electron-selective layer (ESL) material is also very important. The ESL is not only crucial to achieving high photovoltaic conversion efficiency PCE, but also for the device stability. Compared with other metal oxide, ZnO is particularly promising act as ESL, because of its high transparency, suitable work function, and high electron mobility. In addition, low-content doping/modification of metal oxides has been considered as a way of improving the selectivity of ESLs. Here, we have applied Zn_1-xMg_xO as ESL in MAPbI₃ perovskite solar cells. We find that the conduction band edge position of the Zn_1-xMg_xO layer can be tuned upward continuously via increasing x, and the photovoltaic performance, especially Voc depends greatly on x. The devices based on Zn_0.9Mg_0.1O ESL exhibited the best photovoltaic performance and a PCE of ~15.5% was achieved.
In this work, we used, transient photovoltage decay measurements, temperature and light intensity-dependent voltage and electrochemical impedance spectroscopy measurements to investigate carrier transport and recombination mechanism of typical Zn_1-xMg_xO/MAPbI₃ solar cells in this way, to better showed the light on the carrier transport and recombination are determined by the carrier concentration, surface defect and conduction band offset in perovskite solar cells.