應用於鈣鈦礦太陽能電池之金屬氧化物電荷傳導層之物理合成法

Physical Synthesis of Metal Oxide Charge Transporting Layer for Efficient and Stable Perovskite Solar Cells

馬瑞歡(Singh, Mriganka)

指導教授 ： 林宏洲 ； 朱治偉

國立交通大學/工學院/材料科學與工程系所/博士(2019年)

摘要

This thesis work is sum-up into four main chapters which belongs to the four indivisible manuscript and all work based on the physical synthesis and fabrication route of metal oxides charge transporting layers towards cost assessment and stability. And those metal oxides introduces electron transporting materials such as TiO2, SnO2 and hole transporting materials such as NiO in perovskite solar cells (PSCs). In the first work, we have prepared the elctron tranporting material (TiO2) by physical synthesis method and shows the efficient small area and modules based PSCs. In the second work, we did the facile synthesis of composite SnO2 nanostructure for high-performance and showed the excellent device stability of PSCs. In the third work, we have prepared the NiO material by physical synthesis method and used as abipolar metal oxides transportoing layer for efficient PSCs. And, finally, in the last work, we have used this physical synthesis prepared materials and used to make the all soution-processed metal oxides charge transporting layer for efficient PSCs.

關鍵字

金属氧化物 ； 有效率的 ； 稳定 ； 钙钛矿太阳能电池

並列摘要

The extremely rapid progress of perovskite solar cell (PSC) demonstrates the game-changing potential of this class of solar cells for the next generation of photovoltaics (PV) technology. To speed up the transition of PSCs from laboratory stage to the large-scale industrial productions, the issue of device stability while maintaining his good efficiency is at the top priority needed to be overcome. While intensive research efforts have been devoted to improving the power conversion efficiency (PCE) of PSCs, the development of strategies for enhancing the long-term stability of PSCs is equally essential. Metal oxide charge transporting layer based PSCs have potential to be get rid of those issues to commercialization for next-generation solar cells. This work divided into three significant portions about the physical synthesis of various kinds of charge transporting layers along with exploring their unique application for each work. Solution-processed metal oxide charge transporting layers have been carried out widely in organic-inorganic lead halide PSCs due to excellent environmental stability, electronic and optical properties.
In chapter three, a facile method was developed for anatase titanium dioxide (an-TiO2) as the electron transporting layer (ETL) in planar-heterojunction PSCs. This is an inexpensive method for the massive-scale production of ETLs at room temperature to form a suspension of TiO2 nanoparticles (NPs). The lowest unoccupied molecular orbital (LUMO) of ground an-TiO2 NPs, estimated using ultraviolet photoelectron spectroscopy (UPS), was 4.06 eV, which is a salient feature for the active layer. When using a ground an-TiO2 NPs as the ETL, the resulting CH3NH3PbI3-based PSCs exhibited a champion PCE of 17.43%, with a small active area of 0.1 cm2. We were used the same strategy to fabricate a large-area of CH3NH3PbI3 film (designated area: 25.2 cm2) and achieved a PCE of 14.19%. PSC devices were incorporating the ground an-TiO2 NPs as ETLs exhibited attractive long-term device stabilities, with PCEs retaining approximately 85% of their initial values after 80 days.

In chapter four, an alternative to the TiO2 ETL is a tin oxide (SnO2) ETL, was developed for planar PSCs. A novel solid-state synthesis was first employed to prepare a high-quality chemically pure ground SnO2 nanoparticles (G-SnO2) ETL, and a sol–gel process was used to prepare a compact SnO2 (C-SnO2) layer. This bilayer was called as composite tin oxide nanostructures for application in PSCs, which is displaying high PCE and good device stability. The effects of various types of ETLs (C-SnO2, G-SnO2, composite G-SnO2/C-SnO2) on the performance of the PSCs were discussed. The composite SnO2 nanostructure formed a robust ETL having efficient carrier transport properties; accordingly, carrier recombination between the ETL and mixed perovskite was inhibited. PSCs were incorporating C-SnO2, G-SnO2, and G-SnO2/C-SnO2 as ETLs provided PCEs of 16.46, 17.92, and 21.09%, respectively. In addition to their high efficiency, the devices featuring the composite SnO2 (G-SnO2/C-SnO2) nanostructures possessed excellent long-term stability—they maintained 89% (with encapsulation) and 83% (without encapsulation) of their initial PCEs after 105 days (>2500 h) and 60 days (>1400 h), respectively, when stored under dry ambient air (20 ± 5 RH %).
In chapter five, we have developed a facile intercalation method to allow metal oxide to behave bipolar transporting capability for optoelectronic applications. Nickel oxide (NiO) surface-intercalated with cesium carbonate (Cs2CO3) was used as hole and electron transport layers applicable to inverted and planar perovskite solar cells (PSCs). As a result, the champion PCE for the inverted and planar based PSCs has been reached up to 12.08, and 13.98%, respectively.
In conclusion, a new physical synthesis to fabricate metal oxide charge transporting layers for PSCs was developed. The outstanding device stability, massive scale-up, high efficiency, and bipolar nature of metal oxide were presented in detail.

並列關鍵字

Metal Oxide ； Efficient ； Stable ； Perovskite Solar Cells

參考文獻

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4. Jiang, Q.; Zhao, Y.; Zhang, X.; Yang, X.; Chen, Y.; Chu, Z.; Ye, Q.; Li, X.; Yin, Z.; You, J., "Surface Passivation of Perovskite Film for Efficient Solar Cells", Nature Photonics, 13, 460, 2019.

5. Jung, E. H.; Jeon, N. J.; Park, E. Y.; Moon, C. S.; Shin, T. J.; Yang, T.-Y.; Noh, J. H.; Seo, J., "Efficient, Stable and Scalable Perovskite Solar Cells using Poly (3-hexylthiophene)", Nature, 567, 511, 2019.