scholarly journals Revealing the charge carrier kinetics in perovskite solar cells affected by mesoscopic structures and defect states from simple transient photovoltage measurements

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rahmat Hidayat ◽  
Adhita Asma Nurunnizar ◽  
Alvin Fariz ◽  
Herman ◽  
Erlyta Septa Rosa ◽  
...  
Keyword(s):  
Solar Cells ◽  
Short Interval ◽  
Perovskite Solar Cells ◽  
Crystal Defects ◽  
Transport Layer ◽  
Time Range ◽  
Trap States ◽  
Defect States ◽  
Perovskite Layer ◽  
Transient Photovoltage

Abstract This report shows that, by using simple transient photovoltage (TPV) measurements, we can reveal a significant correlation between the TPV decay characteristics and the performance of these perovskite solar cells. TPV decay seems to be composed of a rising part in a short interval after photoexcitation and a long decaying part that extends up to tens of milliseconds. These decay behaviors look different depending on the mesoscopic structures and the perovskite morphology formed therein, as seen from their Scanning Electron Microcopy images and X-ray diffraction patterns. The decay part can be fitted with a three-exponential decay, which reflects different kinetics of electrons in the perovskite/TiO2 layer. On the other hand, the rising part must be fit by a decay equation derived by employing the convolution theorem, where the rising part can be assigned to the electron transport process inside the perovskite layer and the decaying part can be assigned to electron back-transfer. The characteristics can be then understood by considering the effect of crystal defects and trap states in the perovskite grains and perovskite interface with its transport layer, which is TiO2 in this study. Although the TPV decay occurs in a time range much longer than the primary process of photoexcitation as commonly observed in transient photoluminescence spectroscopy, the processes involved in this TPV strongly correlates with the performance of these perovskite solar cells.

scholarly journals Effect of SnO2 Colloidal Dispersion Solution Concentration on the Quality of Perovskite Layer of Solar Cells

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 591
Author(s):  
Keke Song ◽  
Xiaoping Zou ◽  
Huiyin Zhang ◽  
Chunqian Zhang ◽  
Jin Cheng ◽  
...  
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
High Efficiency ◽  
Surface Condition ◽  
Perovskite Solar Cells ◽  
Colloidal Dispersion ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Perovskite Layer ◽  
Dispersion Solution

The electron transport layer (ETL) is critical to carrier extraction for perovskite solar cells (PSCs). Moreover, the morphology and surface condition of the ETL could influence the topography of the perovskite layer. ZnO, TiO2, and SnO2 were widely investigated as ETL materials. However, TiO2 requires a sintering process under high temperature and ZnO has the trouble of chemical instability. SnO2 possesses the advantages of low-temperature fabrication and high conductivity, which is critical to the performance of PSCs prepared under low temperature. Here, we optimized the morphology and property of SnO2 by modulating the concentration of a SnO2 colloidal dispersion solution. When adjusting the concentration of SnO2 colloidal dispersion solution to 5 wt.% (in water), SnO2 film indicated better performance and the perovskite film has a large grain size and smooth surface. Based on high efficiency (16.82%), the device keeps a low hysteresis index (0.23).

scholarly journals CuI/Spiro-OMeTAD Double-Layer Hole Transport Layer to Improve Photovoltaic Performance of Perovskite Solar Cells

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 978
Author(s):  
Chaoqun Lu ◽  
Weijia Zhang ◽  
Zhaoyi Jiang ◽  
Yulong Zhang ◽  
Cong Ni
Keyword(s):  
Solar Cells ◽  
Double Layer ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Photoelectric Conversion Efficiency ◽  
Photoelectric Conversion ◽  
Perovskite Layer

The hole transport layer (HTL) is one of the main factors affecting the efficiency and stability of perovskite solar cells (PSCs). However, obtaining HTLs with the desired properties through current preparation techniques remains a challenge. In the present study, we propose a new method which can be used to achieve a double-layer HTL, by inserting a CuI layer between the perovskite layer and Spiro-OMeTAD layer via a solution spin coating process. The CuI layer deposited on the surface of the perovskite film directly covers the rough perovskite surface, covering the surface defects of the perovskite, while a layer of CuI film avoids the defects caused by Spiro-OMetad pinholes. The double-layer HTLs improve roughness and reduce charge recombination of the Spiro-OMeTAD layer, thereby resulting in superior hole extraction capabilities and faster hole mobility. The CuI/Spiro-OMeTAD double-layer HTLs-based devices were prepared in N2 gloveboxes and obtained an optimized PCE (photoelectric conversion efficiency) of 17.44%. Furthermore, their stability was improved due to the barrier effect of the inorganic CuI layer on the entry of air and moisture into the perovskite layer. The results demonstrate that another deposited CuI film is a promising method for realizing high-performance and air-stable PSCs.

scholarly journals Boosting efficiency of planar heterojunction perovskite solar cells by a low temperature TiCl4 treatment

2018 ◽  
Vol 08 (02) ◽  
pp. 1850009
Author(s):  
Enqi Wang ◽  
Peng Chen ◽  
Xingtian Yin ◽  
Bowen Gao ◽  
Wenxiu Que
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
Surface Defects ◽  
Perovskite Solar Cells ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Trap States ◽  
Control Devices ◽  
Planar Heterojunction ◽  
Better Than

It is well known that electron transport layer (ETL) plays an indispensable role in the planar heterojunction perovskite solar cells (PSCs). TiO2 is widely used as an ETL material due to its excellent transport properties, however, the presence of defects in the TiO2 layer diminishes the power conversion efficiency (PCE) of the devices. Herein, we introduce a method of low-temperature TiCl4 treatment to deposit a TiOx layer on the surface of TiO2 film, which can effectively passivate trap states at the TiO2 surface. Moreover, the treating process is optimized to be 30[Formula: see text]min using a 40[Formula: see text]mM TiCl4 aqueous solution. Benefiting from this, we obtain the champion device with the highest PCE of 18.47%, which is mainly due to the reduction of surface defects and the deposition of the well-crystallized perovskite films. Besides, the modified PSCs exhibit an average PCE of 17.59%, which is much better than the control devices.

scholarly journals Facile NiOx Sol-Gel Synthesis Depending on Chain Length of Various Solvents without Catalyst for Efficient Hole Charge Transfer in Perovskite Solar Cells

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1227 ◽  
Author(s):  
Byung Kim ◽  
Woongsik Jang ◽  
Dong Wang
Keyword(s):  
Solar Cells ◽  
Chain Length ◽  
Short Circuit ◽  
Sol Gel ◽  
Perovskite Solar Cells ◽  
Open Circuit ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Perovskite Layer

Nickel oxide (NiOx)–based perovskite solar cells (PSCs) have recently gained considerable interest, and exhibit above 20% photovoltaic efficiency. However, the reported syntheses of NiOx sol-gel used toxic chemicals for the catalysts during synthesis, which resulted in a high-temperature annealing requirement to remove the organic catalysts (ligands). Herein, we report a facile “NiOx sol-gel depending on the chain length of various solvents” method that eschews toxic catalysts, to confirm the effect of different types of organic solvents on NiOx synthesis. The optimized conditions of the method resulted in better morphology and an increase in the crystallinity of the perovskite layer. Furthermore, the use of the optimized organic solvent improved the absorbance of the photoactive layer in the PSC device. To compare the electrical properties, a PSC was prepared with a p-i-n structure, and the optimized divalent alcohol-based NiOx as the hole transport layer. This improved the charge transport compared with that for the typical 1,2-ethanediol (ethylene glycol) used in earlier studies. Finally, the optimized solvent-based NiOx enhanced device performance by increasing the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF), compared with those of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)–based devices.

scholarly journals Efficient Solution Processed CH3NH3PbI3 Perovskite Solar Cells with PolyTPD Hole Transport Layer

2019 ◽  
Vol 74 (8) ◽  
pp. 665-672 ◽  
Author(s):  
Julian Höcker ◽  
David Kiermasch ◽  
Philipp Rieder ◽  
Kristofer Tvingstedt ◽  
Andreas Baumann ◽  
...  
Keyword(s):  
Solar Cells ◽  
Surface Coverage ◽  
Energy Levels ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Perovskite Layer ◽  
Solvent Engineering ◽  
Highest Occupied Molecular Orbital

AbstractThe organic and hydrophobic polymer poly[N, N′-bis(4-butilphenyl)-N, N′-bis(phenyl)-benzidine] (polyTPD) represents a promising hole transport layer (HTL) for perovskite photovoltaics due to its suitable energy levels, whereby its highest occupied molecular orbital level matches well with the valence band level of methylammonium lead triiodide (CH3NH3PbI3, MAPbI3) perovskite. However, processing a perovskite layer from the solution on the surface of this organic material, is found to be difficult due to the surface properties of the latter. In this study, we evaluate efficient p-i-n type MAPbI3 perovskite solar cells employing differently processed polyTPD layers. We found that the surface coverage of the MAPbI3 perovskite layer strongly depends on the preparation method of the underlying polyTPD layer. By varying the solvents for the polyTPD precursor, its concentration, and by applying an optimised two-step perovskite deposition technique we increased both the surface coverage of the perovskite layer as well as the power conversion efficiency (PCE) of the corresponding solar cell devices. Our simple solvent-engineering approach demonstrates that no further interface modifications are needed for a successful preparation of efficient planar photovoltaic devices with PCEs in the range of 15 %–16 %.

scholarly journals Enhanced Efficiencies of Perovskite Solar Cells by Incorporating Silver Nanowires into the Hole Transport Layer

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 682 ◽  
Author(s):  
Chien-Jui Cheng ◽  
Rathinam Balamurugan ◽  
Bo-Tau Liu
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Silver Nanowires ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Perovskite Layer ◽  
Iodide Ions ◽  
Poly Styrene Sulfonate

In this study, we incorporated silver nanowires (AgNWs) into poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a hole transport layer (HTL) for inverted perovskite solar cells (PVSCs). The effect of AgNW incorporation on the perovskite crystallization, charge transfer, and power conversion efficiency (PCE) of PVSCs were analyzed and discussed. Compared with neat PEDOT:PSS HTL, incorporation of few AgNWs into PEDOT:PSS can significantly enhance the PCE by 25%. However, the AgNW incorporation may result in performance overestimation due to the lateral charge transfer. The corrosion of AgNWs with a perovskite layer was discussed. Too much AgNW incorporation may lead to defects on the interface between the HTL and the perovskite layer. An extra PEDOT:PSS layer over the pristine PEDOT:PSS-AgNW layer can prevent AgNWs from corrosion by iodide ions.

scholarly journals A Water-Stable Organic-Inorganic Hybrid Perovskite for Solar Cells by Inorganic Passivation

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 83 ◽  
Author(s):  
Edward Guangqing Tai ◽  
Ryan Taoran Wang ◽  
Jason Yuanzhe Chen ◽  
Gu Xu
Keyword(s):  
Solar Cells ◽  
Uv Light ◽  
Perovskite Solar Cells ◽  
Transport Layer ◽  
Bandgap Energy ◽  
Lead Iodide ◽  
Perovskite Layer ◽  
Rapid Degradation ◽  
Inorganic Hybrid ◽  
Hybrid Perovskite

Organic-inorganic hybrid halide perovskite solar cells (PSCs) have been a trending topic in recent years. Significant progress has been made to increase their power conversion efficiency (PCE) to more than 20%. However, the poor stability of PSCs in both working and non-working conditions results in rapid degradation through multiple environmental erosions such as water, heat, and UV light. Attempts have been made to resolve the rapid-degradation problems, including formula changes, transport layer improvements, and encapsulations, but none of these have effectively resolved the dilemma. This paper reports our findings on adding inorganic films as surface-passivation layers on top of the hybrid perovskite materials, which not only enhance stability by eliminating weak sites but also prevent water penetration by using a water-stable layer. The surface-passivated hybrid perovskite layer indicates a slight increase of bandgap energy (Eg=1.76 eV), compared to the original methylammonium lead iodide (MAPbI3, Eg=1.61 eV) layer, allowing for more stable perovskite layer with a small sacrifice in the photoluminescence property, which represents a lower charge diffusion rate and higher bandgap energy. Our finding offers an alternative approach to resolving the low stability issue for PSC fabrication.

scholarly journals Metal Oxide Compact Electron Transport Layer Modification for Efficient and Stable Perovskite Solar Cells

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2207 ◽  
Author(s):  
Md. Shahiduzzaman ◽  
Shoko Fukaya ◽  
Ersan Y. Muslih ◽  
Liangle Wang ◽  
Masahiro Nakano ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Metal Oxide ◽  
Perovskite Solar Cells ◽  
Clean Energy ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Future Research ◽  
Perovskite Layer ◽  
And Performance

Perovskite solar cells (PSCs) have appeared as a promising design for next-generation thin-film photovoltaics because of their cost-efficient fabrication processes and excellent optoelectronic properties. However, PSCs containing a metal oxide compact layer (CL) suffer from poor long-term stability and performance. The quality of the underlying substrate strongly influences the growth of the perovskite layer. In turn, the perovskite film quality directly affects the efficiency and stability of the resultant PSCs. Thus, substrate modification with metal oxide CLs to produce highly efficient and stable PSCs has drawn attention. In this review, metal oxide-based electron transport layers (ETLs) used in PSCs and their systemic modification are reviewed. The roles of ETLs in the design and fabrication of efficient and stable PSCs are also discussed. This review will guide the further development of perovskite films with larger grains, higher crystallinity, and more homogeneous morphology, which correlate to higher stable PSC performance. The challenges and future research directions for PSCs containing compact ETLs are also described with the goal of improving their sustainability to reach new heights of clean energy production.

scholarly journals Improved efficiency and reduced hysteresis in ultra-stable fully printable mesoscopic perovskite solar cells through incorporation of CuSCN into the perovskite layer

2019 ◽  
Vol 7 (14) ◽  
pp. 8073-8077 ◽  
Author(s):  
Iwan Zimmermann ◽  
Paul Gratia ◽  
David Martineau ◽  
Giulia Grancini ◽  
Jean-Nicolas Audinot ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Perovskite Layer ◽  
Term Stability ◽  
Long Term Stability ◽  
Carbon Based

Improved charge extraction in carbon-based fully printable hole transport layer-free mesoscopic perovskite solar cells with excellent long-term stability.

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