Perspective on Predominant Metal Oxide Charge Transporting Materials for High-Performance Perovskite Solar Cells

Abstract

Nowadays, the power conversion efficiency of organometallic mixed halide perovskite solar cells (PSCs) is beyond 25%. To fabricate highly efficient and stable PSCs, the performance of metal oxide charge transport layers (CTLs) is one of the key factors. The CTLs are employed in PSCs to separate the electrons and holes generated in the perovskite active layer, suppressing the charge recombination rate so that the charge collection efficiency can be increased at their respective electrodes. In general, engineering of metal oxide electron transport layers (ETLs) is found to be dominated in the research community to boost the performance of PSCs due to the resilient features of ETLs such as excellent electronic properties, high resistance to thermal temperature and moisture, ensuring good device stability as well as their high versatility in material preparation. The metal oxide hole transport layers in PSCs are recently intensively studied. The performance of PSCs is found to be very promising by using optimized hole transport materials. This review concisely discusses the evolution of some prevalent metal oxide charge transport materials (CTMs) including TiO2, SnO2, and NiOx, which are able to yield high-performance PSCs. The article begins with introducing the development trend of PSCs using different types of CTLs, pointing out the important criteria for metal oxides being effective CTLs, and then a variety of preparation methods for CTLs as employed by the community for high-performance PSCs are discussed. Finally, the challenges and prospects for future research direction toward scalable metal oxide CTM-based PSCs are delineated.

A Stable Aqueous SnO2 Nanoparticle Dispersion for Roll-to-Roll Fabrication of Flexible Perovskite Solar Cells

“…Underlying this is a need that all advances need to be achieved using scalable deposition approaches to avoid the "spin-coating hurdle" induced by the difficulty to translate between small, spin-coated devices and those fabricated using more commercially-ready approaches. Here, we address the key challenge of developing cheap, stable, and scalable nanomaterials that can be applied using industrially-relevant coating or printing methods to achieve electron transporting layers (ETL) suitable for efficient PSCs [7,8].…”

Laser modification of Au–CuO–Au structures for improved electrical and electro-optical properties

“…Their nanomaterials have shown great potential in various applications such as photocatalysis [1][2][3][4][5], bio-sensors [6][7][8][9], and bio-medicine [10][11][12][13]. Due to the high surface-volume ratio and quantum-size effects in nanoscale systems, onedimensional metal-oxide-semiconductor nanomaterials, including metal-oxide nanowires, have become essential building blocks in the construction and assembly of many nano-devices such as solar cells [14][15][16][17][18], photodetectors , [19][20][21][22][23] gas sensors [24][25][26][27][28], and memristors [29][30][31][32][33]. To fabricate functional nano-devices, metal-oxide nanowires are often connected to metal electrodes to establish a metal-semiconductor-metal (MSM) nano-structure.…”

A Morphological Study of Solvothermally Grown SnO2 Nanostructures for Application in Perovskite Solar Cells

“…Recently, SnO 2 materials have become a popular option for ETL used in PSCs due to a number of advantages. It has a higher electron mobility (around 100–250 cm 2 /V·s) compared to TiO 2 (<1 cm 2 /V·s) [ 53 ] and possesses a deep conduction band, aligning well with the perovskites, leading to a higher open-circuit voltage ( V OC ) of PSCs. Meanwhile, SnO 2 is not an active photocatalytic material, which is one of the desired properties for the chemical stability of the photovoltaic materials as well as the lifetime of the devices.…”