Effects of TiO2 Properties on Performance of CH3NH3PbI3 Perovskite Photovoltaic Cells

ABSTRACTThe effects of TiCl4 post-treatment on the physicochemical properties of porous TiO2 (pTiO2) layers fabricated at 300 °C and 400 °C (denoted as pTiO2(300) and pTiO2(400), respectively) in CH3NH3PbI3 perovskite photovoltaic cells were investigated. Water contents (physisorbed water and water derived from surface hydroxyl groups) of pTiO2(300) and pTiO2(400) before and after TiCl4 post-treatment were measured by using temperature desorption spectroscopy (TDS). Moreover, structural analysis of the CH3NH3PbI3 perovskite part was performed by X-ray diffraction (XRD). In the case of pTiO2(300), the content of water was increased by the TiCl4 post-treatment due to the removal of residual organic compounds that existed before the treatment. It then caused a change in the surface activity of pTiO2(300) and enhancement of solar cell performance and photocurrent density, though suppression of CH3NH3PbI3 perovskite formation occurred. In comparison, contents of water were decreased for pTiO2(400), leading to enhancement of the conversion of PbI2 to CH3NH3PbI3 perovskite. As a result, there were significant increases in short circuit current density (Jscs) and PCEs. The results showed that TiCl4 post-treatment is an effective approach to prepare high-performance CH3NH3PbI3 perovskite solar cells without heat treatment at a very high temperature.

Download Full-text

Antireflection Improvement and Junction Quality Optimization of Si/PEDOT:PSS Solar Cell with the Introduction of Dopamine@Graphene

Energies ◽

10.3390/en13225986 ◽

2020 ◽

Vol 13 (22) ◽

pp. 5986

Author(s):

Tao Chen ◽

Hao Guo ◽

Leiming Yu ◽

Tao Sun ◽

Anran Chen ◽

...

Keyword(s):

Solar Cell ◽

Conversion Efficiency ◽

High Performance ◽

Electrochemical Impedance ◽

Short Circuit ◽

Short Circuit Current ◽

Electrochemical Impedance Spectra ◽

Solar Cell Performance ◽

Photovoltaic Conversion ◽

Photovoltaic Conversion Efficiency

Si/PEDOT: PSS solar cell is an optional photovoltaic device owing to its promising high photovoltaic conversion efficiency (PCE) and economic manufacture process. In this work, dopamine@graphene was firstly introduced between the silicon substrate and PEDOT:PSS film for Si/PEDOT: PSS solar cell. The dopamine@graphene was proved to be effective in improving the PCE, and the influence of mechanical properties of dopamine@graphene on solar cell performance was revealed. When dopamine@graphene was incorporated into the cell preparation, the antireflection ability of the cell was enhanced within the wavelength range of 300~450 and 650~1100 nm. The enhanced antireflection ability would benefit amount of the photon-generated carriers. The electrochemical impedance spectra test revealed that the introduction of dopamine@graphene could facilitate the separation of carriers and improve the junction quality. Thus, the short-circuit current density and fill factor were both promoted, which led to the improved PCE. Meanwhile, the influence of graphene concentration on device performances was also investigated. The photovoltaic conversion efficiency would be promoted from 11.06% to 13.15% when dopamine@graphene solution with concentration 1.5 mg/mL was applied. The achievements of this study showed that the dopamine@graphene composites could be an useful materials for high-performance Si/PEDOT:PSS solar cells.

Download Full-text

Iodide management in formamidinium-lead-halide–based perovskite layers for efficient solar cells

Science ◽

10.1126/science.aan2301 ◽

2017 ◽

Vol 356 (6345) ◽

pp. 1376-1379 ◽

Cited By ~ 3378

Author(s):

Woon Seok Yang ◽

Byung-Wook Park ◽

Eui Hyuk Jung ◽

Nam Joong Jeon ◽

Young Chan Kim ◽

...

Keyword(s):

Solar Cells ◽

High Performance ◽

Deep Level ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Small Cells ◽

Iodide Ions

The formation of a dense and uniform thin layer on the substrates is crucial for the fabrication of high-performance perovskite solar cells (PSCs) containing formamidinium with multiple cations and mixed halide anions. The concentration of defect states, which reduce a cell’s performance by decreasing the open-circuit voltage and short-circuit current density, needs to be as low as possible. We show that the introduction of additional iodide ions into the organic cation solution, which are used to form the perovskite layers through an intramolecular exchanging process, decreases the concentration of deep-level defects. The defect-engineered thin perovskite layers enable the fabrication of PSCs with a certified power conversion efficiency of 22.1% in small cells and 19.7% in 1-square-centimeter cells.

Download Full-text

Improving the Morphology of the Perovskite Absorber Layer in Hybrid Organic/Inorganic Halide Perovskite MAPbI3 Solar Cells

Journal of Solar Energy ◽

10.1155/2017/8549847 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

I. J. Ogundana ◽

S. Y. Foo

Keyword(s):

Thin Film ◽

Solar Cells ◽

High Performance ◽

Short Circuit ◽

Photovoltaic Performance ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Perovskite Layer ◽

Large Variability

Recently, perovskite solar cells have attracted tremendous attention due to their excellent power conversion efficiency, low cost, simple fabrications, and high photovoltaic performance. Furthermore, the perovskite solar cells are lightweight and possess thin film and semitransparency. However, the nonuniformity in perovskite layer constitutes a major setback to the operation mechanism, performance, reproducibility, and degradation of perovskite solar cells. Therefore, one of the main challenges in planar perovskite devices is the fabrication of high quality films with controlled morphology and least amount of pin-holes for high performance thin film perovskite devices. The poor reproducibility in perovskite solar cells hinders the accurate fabrication of practical devices for use in real world applications, and this is primarily as a result of the inability to control the morphology of perovskites, leading to large variability in the characteristics of perovskite solar cells. Hence, the focus of research in perovskites has been mostly geared towards improving the morphology and crystallization of perovskite absorber by selecting the optimal annealing condition considering the effect of humidity. Here we report a controlled ambient condition that is necessary to grow uniform perovskite crystals. A best PCE of 7.5% was achieved along with a short-circuit current density of 15.2 mA/cm2, an open-circuit voltage of 0.81 V, and a fill factor of 0.612 from the perovskite solar cell prepared under 60% relative humidity.

Download Full-text

Facile Synthesis of Spherical TiO2 Hollow Nanospheres with a Diameter of 150 nm for High-Performance Mesoporous Perovskite Solar Cells

Materials ◽

10.3390/ma14030629 ◽

2021 ◽

Vol 14 (3) ◽

pp. 629

Author(s):

Hoang Van Quy ◽

Dang Hai Truyen ◽

Sangmo Kim ◽

Chung Wung Bark

Keyword(s):

Solar Cells ◽

High Performance ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Synthesis Method ◽

Short Circuit Current ◽

Transport Layer ◽

Electron Transport Layer ◽

Hollow Nanospheres ◽

Facile Synthesis

The electron transport layer (ETL) of organic–inorganic perovskite solar cells plays an important role in their power conversion efficiency (PCE). In this study, TiO2 hollow nanospheres with a diameter of 150 nm were prepared by a facile synthesis method. The synthesized TiO2 hollow nanospheres had a highly porous structure with a surface area of 85.23 m2 g−1, which is significantly higher than commercial TiO2 (P25) (54.32 m2 g−1), indicating that they can form an ideal mesoporous layer for Formamidinium iodide-based perovskite solar cells (PSCs). In addition, the nanospheres achieved a remarkable perovskite performance, and the average PCE increased from 12.87% to 14.27% with a short circuit current density of 22.36 mAcm−2, an open voltage of 0.95 V, and a fill factor of 0.65. The scanning electron microscopy images revealed that the enhanced PCE could be due to the improved carrier collection and transport properties of the nanosphere, which enabled efficient filtration of perovskite into the TiO2 mesoporous ETL. The TiO2 hollow nanospheres fabricated in this study show high potential as a high-quality ETL material for efficient (FAPbI3)0.97(MAPbBr3)0.03-based PSCs.

Download Full-text

High Performance Planar Structure Perovskite Solar Cells Using a Solvent Dripping Treatment on Hole Transporting Layer

Coatings ◽

10.3390/coatings10020127 ◽

2020 ◽

Vol 10 (2) ◽

pp. 127 ◽

Cited By ~ 2

Author(s):

Xuhui Wang ◽

Gang Lu ◽

Min Zhang ◽

Yali Gao ◽

Yanbo Liu ◽

...

Keyword(s):

Solar Cells ◽

Charge Carrier ◽

High Performance ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Solution Treatment ◽

Short Circuit Current ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer

Perovskite solar cell efficiency is not only related with material properties, but also affected by the interface engineering that used in perovskite solar cells. The perovskite film/electrode interface properties play important roles in charge carrier extraction, transport, and recombination. To achieve better interface contact for the device operation, proper interlayers or surface treatment should be applied. In this study, we applied a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) interlayer with a solvent/solution washing treatment as the hole transport layer. It showed that by the solvent/solution treatment, the PEDOT:PSS film conductivity was significantly enhanced, and hence, the charge carrier transfer efficiency was efficiently improved, and the device short-circuit current density was enlarged. Finally, the device efficiency significantly increased from 14.8% to 16.2%.

Download Full-text

Multi-Walled Carbon Nanotube-Assisted Encapsulation Approach for Stable Perovskite Solar Cells

Molecules ◽

10.3390/molecules26165060 ◽

2021 ◽

Vol 26 (16) ◽

pp. 5060

Author(s):

Jin-Myung Choi ◽

Hiroki Suko ◽

Kyusun Kim ◽

Jiye Han ◽

Sangsu Lee ◽

...

Keyword(s):

Solar Cells ◽

Carbon Nanotube ◽

High Performance ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Stable Operation ◽

Cover Glass ◽

Multi Walled Carbon Nanotube

Perovskite solar cells (PSCs) are regarded as the next-generation thin-film energy harvester, owing to their high performance. However, there is a lack of studies on their encapsulation technology, which is critical for resolving their shortcomings, such as their degradation by oxygen and moisture. It is determined that the moisture intrusion and the heat trapped within the encapsulating cover glass of PSCs influenced the operating stability of the devices. Therefore, we improved the moisture and oxygen barrier ability and heat releasing capability in the passivation of PSCs by adding multi-walled carbon nanotubes to the epoxy resin used for encapsulation. The 0.5 wt% of carbon nanotube-added resin-based encapsulated PSCs exhibited a more stable operation with a ca. 30% efficiency decrease compared to the ca. 63% decrease in the reference devices over one week under continuous operation. Specifically, the short-circuit current density and the fill factor, which are affected by moisture and oxygen-driven degradation, as well as the open-circuit voltage, which is affected by thermal damage, were higher for the multi-walled carbon nanotube-added encapsulated devices than the control devices, after the stability test.

Download Full-text

Low temperature synthesis of hierarchical TiO2 nanostructures for high performance perovskite solar cells by pulsed laser deposition

Physical Chemistry Chemical Physics ◽

10.1039/c6cp02896a ◽

2016 ◽

Vol 18 (39) ◽

pp. 27067-27072 ◽

Cited By ~ 17

Author(s):

Bin Yang ◽

Masoud Mahjouri-Samani ◽

Christopher M. Rouleau ◽

David B. Geohegan ◽

Kai Xiao

Keyword(s):

Pulsed Laser Deposition ◽

High Performance ◽

Photovoltaic Cells ◽

Perovskite Solar Cells ◽

Pulsed Laser ◽

Laser Deposition ◽

Low Temperature Synthesis ◽

Temperature Synthesis ◽

Tio2 Nanostructures ◽

Perovskite Photovoltaic

High aspect-ratio TiO2 nanostructures directly assembled with pulsed laser deposition could improve interfacial contact for superior perovskite photovoltaic cells.

Download Full-text

Post-treatment techniques for high-performance perovskite solar cells

MRS Bulletin ◽

10.1557/mrs.2020.141 ◽

2020 ◽

Vol 45 (6) ◽

pp. 431-438 ◽

Cited By ~ 1

Author(s):

Shuang Xiao ◽

Yu Li ◽

Shizhao Zheng ◽

Shihe Yang

Keyword(s):

Solar Cells ◽

High Performance ◽

Perovskite Solar Cells ◽

Post Treatment ◽

Treatment Techniques ◽

Image Position

Abstract

Download Full-text

The Influence of the Thickness of Compact TiO2 Electron Transport Layer on the Performance of Planar CH3NH3PbI3 Perovskite Solar Cells

Materials ◽

10.3390/ma14123295 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3295

Author(s):

Andrzej Sławek ◽

Zbigniew Starowicz ◽

Marek Lipiński

Keyword(s):

Solar Cells ◽

Electron Transport ◽

Short Circuit ◽

Photovoltaic Performance ◽

Perovskite Solar Cells ◽

Precursor Solution ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Transport Layer ◽

Electron Transport Layer

In recent years, lead halide perovskites have attracted considerable attention from the scientific community due to their exceptional properties and fast-growing enhancement for solar energy harvesting efficiency. One of the fundamental aspects of the architecture of perovskite-based solar cells (PSCs) is the electron transport layer (ETL), which also acts as a barrier for holes. In this work, the influence of compact TiO2 ETL on the performance of planar heterojunction solar cells based on CH3NH3PbI3 perovskite was investigated. ETLs were deposited on fluorine-doped tin oxide (FTO) substrates from a titanium diisopropoxide bis(acetylacetonate) precursor solution using the spin-coating method with changing precursor concentration and centrifugation speed. It was found that the thickness and continuity of ETLs, investigated between 0 and 124 nm, strongly affect the photovoltaic performance of PSCs, in particular short-circuit current density (JSC). Optical and topographic properties of the compact TiO2 layers were investigated as well.

Download Full-text