Recent Progress on Applications of Nano Metal Oxides in Perovskite Solar Cells

doi:10.15541/jim20160026

Abstract

Abstract:

In recent years, the power conversion efficiency of perovskite solar cells (PSCs) has increased dramatically from 3.8% to 20.1%, approaching to that of recent silicon-based solar cells. Inorganic metal oxides, including TiO₂, ZnO, Al₂O₃, etc., have been widely used as charge transport layers and perovskite supporting scaffords in PSCs. Regarding the cell structures of PSCs, this review discusses the syntheses methods of inorganic compact layers and mesoporous layers made from these inorganic metal oxides, and the modifications (including surface modifications, doping and composites) of these inorganic functional layers, which aim at improving the charge transport properties of these layers and changing the interfacial characteristics with perovskites to enhance the PSCs’ cell performances. Besides, the important issues of such functional layers made from inorganic metal oxides are also discussed.

Key words: nano metal oxides, perovskite solar cells, compact layers, mesoporous layers, review

CLC Number:

TQ174

WANG Wei-Qi, ZHENG Hui-Feng, LU Guan-Hong, LIU Yang-Qiao, SUN Jing, GAO Lian. Recent Progress on Applications of Nano Metal Oxides in Perovskite Solar Cells[J]. Journal of Inorganic Materials, 2016, 31(9): 897-907.

Figures/Tables 8

Fig. 1 Schematic energy diagram of hybrid solar cells

Fig. 2 Schematic illustration of quantum dot-sensitized, planar and mesoporous perovskite solar cell architectures[14]

Table 1 Pros and cons of common TiO2 compact layer preparation methods

Method	Thickness	Pinholes	Flexible	Costs
Wet chemisty	Thick	Many	Suitable	Low
Spray pyrolysis	Thick	Few	Unsuitable	Low
ALD	Thin	Few	Suitable	High
Sputtering	Thin	Few	Suitable	High

Fig. 3 Top-view FE-SEM images of TiO2 compact layers fabricated on FTO substrates by different preparation methods[31](a) ALD; (b) Spray pyrolysis; (c) Spin coating. The average thickness of TiO2 is about 50nm in each sample

Fig. 4 AFM images of CH3NH3PbI3 perovskite on (a) bare ZnO and (b) ZnO/C3-SAM. SEM images of CH3NH3PbI3 perovskites on (c) bare ZnO and( d) ZnO/C3-SAM. (e) XRD patterns of perovskite films on ZnO (black line) and ZnO/SAM substrates (red line)[53]

Fig. 5 (a) SEM cross-sectional image of the device and (b) Energy diagram (relative to the vacuum level) of each functional layer in the device [57]

Fig. 6 Schematic fabrication procedure for the TiO2 NB array film based C-PSCs[78](a) PS monolayer; (b) PS monolayer filled with TiO2 sol; (c) TiO2 NB array film; (d) perovskite filled and topped TiO2 NB array; (e) the wrought C-PSC

Fig. 7 Schematic illustrating the charge transfer and charge transport in a perovskite-sensitized TiO2 solar cell (left) and a noninjecting Al2O3-based solar cell (right) [17]A representation of the energy landscape is shown below, with electrons shown as solid circles and holes as open circles

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