Research

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11 pages, 1376 KiB

Open AccessArticle

Controllable Introduction of Surface Defects on CH₃NH₃PbI₃ Perovskite

by Sushu Wan, Yajie Zhu, Daocheng Hong and Yuxi Tian

Nanomaterials 2022, 12(6), 1002; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12061002 - 18 Mar 2022

Cited by 1 | Viewed by 2259

One of the unique characteristics of semiconductors is the strong dependence of their properties on crystal defects and doping. However, due to the species diversity and low density, it is very difficult to control the type and concentration of the defects. In perovskite [...] Read more.

One of the unique characteristics of semiconductors is the strong dependence of their properties on crystal defects and doping. However, due to the species diversity and low density, it is very difficult to control the type and concentration of the defects. In perovskite materials, crystal defects are randomly formed during the fast crystallization process, causing large heterogeneity of the samples. Here, in this work, we report a controllable method to introduce surface defects on CH₃NH₃PbI₃ perovskite materials via the interaction with 1,4-benzoquinone (BQ) molecules on the gas and solid interface. After the adsorption of BQ molecules on the perovskite surface, surface defects can be generated by photoinduced chemical reactions. The concentration of the defects can thus be controlled by precisely regulating the laser irradiation time. The concentration of the defects can be characterized by a gradually decreased PL intensity and lifetime and was found to influence the atmospheric response and the subsequent acetone-induced degradation of the materials. These results demonstrate that crystal defects in perovskite materials can be controllably introduced, which provides a possible way to fully understand the correlation between the nature and chemical structure of these defects. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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11 pages, 1304 KiB

Open AccessArticle

Measuring Exciton Fine-Structure in Randomly Oriented Perovskite Nanocrystal Ensembles Using Nonlinear Optical Spectroscopy: Theory

by Albert Liu

Nanomaterials 2022, 12(5), 801; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12050801 - 26 Feb 2022

Cited by 1 | Viewed by 1671

Abstract

Lead halide perovskite nanocrystals (PNCs) exhibit unique optoelectronic properties, many of which originate from a purported bright-triplet exciton fine-structure. A major impediment to measuring this fine-structure is inhomogeneous spectral broadening, which has limited most experimental studies to single-nanocrystal spectroscopies. It is shown here [...] Read more.

Lead halide perovskite nanocrystals (PNCs) exhibit unique optoelectronic properties, many of which originate from a purported bright-triplet exciton fine-structure. A major impediment to measuring this fine-structure is inhomogeneous spectral broadening, which has limited most experimental studies to single-nanocrystal spectroscopies. It is shown here that the linearly polarized single-particle selection rules in PNCs are preserved in nonlinear spectroscopies of randomly oriented ensembles. Simulations incorporating rotational averaging demonstrate that techniques such as transient absorption and two-dimensional coherent spectroscopy are capable of resolving exciton fine-structure in PNCs, even in the presence of inhomogeneous broadening and orientation disorder. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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11 pages, 2683 KiB

Open AccessArticle

Temperature-Dependent Photoluminescence of Manganese Halide with Tetrahedron Structure in Anti-Perovskites

by Yijie Xia, Shuaishuai Du, Pengju Huang, Luchao Wu, Siyu Yan, Weizhi Wang and Gaoyu Zhong

Nanomaterials 2021, 11(12), 3310; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11123310 - 06 Dec 2021

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Abstract

The temperature-dependent photoluminescence (PL) properties of an anti-perovskite [MnBr₄]BrCs₃ sample in the temperature range of 78–500 K are studied in the present work. This material exhibits unique performance which is different from a typical perovskite. Experiments showed that from room [...] Read more.

The temperature-dependent photoluminescence (PL) properties of an anti-perovskite [MnBr₄]BrCs₃ sample in the temperature range of 78–500 K are studied in the present work. This material exhibits unique performance which is different from a typical perovskite. Experiments showed that from room temperature to 78 K, the luminous intensity increased as the temperature decreased. From room temperature to 500 K, the photoluminescence intensity gradually decreased with increasing temperature. Experiments with varying temperatures repeatedly showed that the emission wavelength was very stable. Based on the above-mentioned phenomenon of the changing photoluminescence under different temperatures, the mechanism is deduced from the temperature-dependent characteristics of excitons, and the experimental results are explained on the basis of the types of excitons with different energy levels and different recombination rates involved in the steady-state PL process. The results show that in the measured temperature range of 78–500 K, the steady-state PL of [MnBr₄]BrCs₃ had three excitons with different energy levels and recombination rates participating. The involved excitons with the highest energy level not only had a high radiative recombination rate, but a high non-radiative recombination rate as well. The excitons at the second-highest energy level had a similar radiative recombination rate to the lowest energy level excitons and a had high non-radiative recombination rate. These excitons made the photoluminescence gradually decrease with increasing temperature. This may be the reason for this material’s high photoluminescence efficiency and low electroluminescence efficiency. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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16 pages, 4413 KiB

Open AccessArticle

Thermal Analysis of Metal-Organic Precursors for Functional Cu:ΝiOx Hole Transporting Layer in Inverted Perovskite Solar Cells: Role of Solution Combustion Chemistry in Cu:ΝiOx Thin Films Processing

by Apostolos Ioakeimidis, Ioannis T. Papadas, Eirini D. Koutsouroubi, Gerasimos S. Armatas and Stelios A. Choulis

Nanomaterials 2021, 11(11), 3074; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11113074 - 15 Nov 2021

Cited by 1 | Viewed by 2130

Abstract

Low temperature solution combustion synthesis emerges as a facile method for the synthesis of functional metal oxides thin films for electronic applications. We study the solution combustion synthesis process of Cu:NiO_x using different molar ratios (w/o, 0.1 and 1.5) of fuel acetylacetone [...] Read more.

Low temperature solution combustion synthesis emerges as a facile method for the synthesis of functional metal oxides thin films for electronic applications. We study the solution combustion synthesis process of Cu:NiO_x using different molar ratios (w/o, 0.1 and 1.5) of fuel acetylacetone (Acac) to oxidizer (Cu, Ni Nitrates) as a function of thermal annealing temperatures 150, 200, and 300 °C. The solution combustion synthesis process, in both thin films and bulk Cu:NiO_x, is investigated. Thermal analysis studies using TGA and DTA reveal that the Cu:NiO_x thin films show a more gradual mass loss while the bulk Cu:NiO_x exhibits a distinct combustion process. The thin films can crystallize to Cu:NiO_x at an annealing temperature of 300 °C, irrespective of the Acac/Oxidizer ratio, whereas lower annealing temperatures (150 and 200 °C) produce amorphous materials. A detail characterization study of solution combustion synthesized Cu:NiO_x, including XPS, UV-Vis, AFM, and Contact angle measurements, is presented. Finally, 50 nm Cu:NiO_x thin films are introduced as HTLs within the inverted perovskite solar cell device architecture. The Cu:NiO_x HTL annealed at 150 and 200 °C provided PVSCs with limited functionality, whereas efficient triple-cation Cs_0.04(MA_0.17FA_0.83)_0.96 Pb(I_0.83Br_0.17)₃-based PVSCs achieved for Cu:NiO_x HTLs for annealing temperature of 300 °C. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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12 pages, 2502 KiB

Open AccessArticle

Performance Enhancement of All-Inorganic Carbon-Based CsPbIBr₂ Perovskite Solar Cells Using a Moth-Eye Anti-Reflector

by Wensheng Lan, Dazheng Chen, Qirui Guo, Baichuan Tian, Xiaoping Xie, Yibing He, Wenming Chai, Gang Liu, Peng Dong, He Xi, Weidong Zhu and Chunfu Zhang

Nanomaterials 2021, 11(10), 2726; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11102726 - 15 Oct 2021

Cited by 5 | Viewed by 2119

Abstract

All-inorganic carbon-based CsPbIBr₂ perovskite solar cells (PSCs) have attracted increasing interest due to the low cost and the balance between bandgap and stability. However, the relatively narrow light absorption range (300 to 600 nm) limited the further improvement of short-circuit current density [...] Read more.

All-inorganic carbon-based CsPbIBr₂ perovskite solar cells (PSCs) have attracted increasing interest due to the low cost and the balance between bandgap and stability. However, the relatively narrow light absorption range (300 to 600 nm) limited the further improvement of short-circuit current density (J_SC) and power conversion efficiency (PCE) of PSCs. Considering the inevitable reflectance loss (~10%) at air/glass interface, we prepared the moth-eye anti-reflector by ultraviolet nanoimprint technology and achieved an average reflectance as low as 5.15%. By attaching the anti-reflector on the glass side of PSCs, the J_SC was promoted by 9.4% from 10.89 mA/cm² to 11.91 mA/cm², which is the highest among PSCs with a structure of glass/FTO/c-TiO₂/CsPbIBr₂/Carbon, and the PCE was enhanced by 9.9% from 9.17% to 10.08%. The results demonstrated that the larger J_SC induced by the optical reflectance modulation of moth-eye anti-reflector was responsible for the improved PCE. Simultaneously, this moth-eye anti-reflector can withstand a high temperature up to 200 °C, and perform efficiently at a wide range of incident angles from 40° to 90° and under various light intensities. This work is helpful to further improve the performance of CsPbIBr₂ PSCs by optical modulation and boost the possible application of wide-range-wavelength anti-reflector in single and multi-junction solar cells. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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13 pages, 3116 KiB

Open AccessArticle

Controlled Growth of Porous InBr₃: PbBr₂ Film for Preparation of CsPbBr₃ in Carbon-Based Planar Perovskite Solar Cells

by Kailin Chi, Hansi Xu, Bingtao Feng, Xianwei Meng, Daoyu Yu and Qian Li

Nanomaterials 2021, 11(9), 2408; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11092408 - 16 Sep 2021

Cited by 1 | Viewed by 2589

Abstract

Due to the low solubility of CsBr in organic solvents, the CsPbBr₃ film prepared by the multi-step method has holes and insufficient thickness, and the light absorption capacity and current density of the perovskite film hinder the further improvement in the power [...] Read more.

Due to the low solubility of CsBr in organic solvents, the CsPbBr₃ film prepared by the multi-step method has holes and insufficient thickness, and the light absorption capacity and current density of the perovskite film hinder the further improvement in the power conversion efficiency (PCE) of CsPbBr₃ solar cells. In this study, we introduced InBr₃ into the PbBr₂ precursor solution and adjusted the concentration of PbBr₂, successfully prepared PbBr₂ with a porous structure on the compact TiO₂ (c-TiO₂) substrate to ensure that it fully reacted with CsBr, and obtained the planar carbon-based CsPbBr₃ solar cells with high-quality perovskite film. The results reveal that the porous PbBr₂ structure and the increasing PbBr₂ concentration are beneficial to increase the thickness of the CsPbBr₃ films, optimize the surface morphology, and significantly enhance the light absorption capacity. Finally, the PCE of the CsPbBr₃ solar cells obtained after conditions optimization was 5.76%. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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Review

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36 pages, 3483 KiB

Open AccessReview

Recent Issues and Configuration Factors in Perovskite-Silicon Tandem Solar Cells towards Large Scaling Production

by Mohammed Islam Elsmani, Noshin Fatima, Michael Paul A. Jallorina, Suhaila Sepeai, Mohd Sukor Su’ait, Norasikin Ahmad Ludin, Mohd Asri Mat Teridi, Kamaruzzaman Sopian and Mohd Adib Ibrahim

Nanomaterials 2021, 11(12), 3186; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11123186 - 24 Nov 2021

Cited by 13 | Viewed by 4316

Abstract

The unprecedented development of perovskite-silicon (PSC-Si) tandem solar cells in the last five years has been hindered by several challenges towards industrialization, which require further research. The combination of the low cost of perovskite and legacy silicon solar cells serve as primary drivers [...] Read more.

The unprecedented development of perovskite-silicon (PSC-Si) tandem solar cells in the last five years has been hindered by several challenges towards industrialization, which require further research. The combination of the low cost of perovskite and legacy silicon solar cells serve as primary drivers for PSC-Si tandem solar cell improvement. For the perovskite top-cell, the utmost concern reported in the literature is perovskite instability. Hence, proposed physical loss mechanisms for intrinsic and extrinsic instability as triggering mechanisms for hysteresis, ion segregation, and trap states, along with the latest proposed mitigation strategies in terms of stability engineering, are discussed. The silicon bottom cell, being a mature technology, is currently facing bottleneck challenges to achieve power conversion efficiencies (PCE) greater than 26.7%, which requires more understanding in the context of light management and passivation technologies. Finally, for large-scale industrialization of the PSC-Si tandem solar cell, the promising silicon wafer thinning, and large-scale film deposition technologies could cause a shift and align with a more affordable and flexible roll-to-roll PSC-Si technology. Therefore, this review aims to provide deliberate guidance on critical fundamental issues and configuration factors in current PSC-Si tandem technologies towards large-scale industrialization. to meet the 2031 PSC-Si Tandem road maps market target. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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16 pages, 2936 KiB

Open AccessReview

Review on Tailoring PEDOT:PSS Layer for Improved Device Stability of Perovskite Solar Cells

by Yijie Xia, Guowang Yan and Jian Lin

Nanomaterials 2021, 11(11), 3119; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11113119 - 19 Nov 2021

Cited by 34 | Viewed by 4664

Abstract

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has high optical transparency in the visible light range and low-temperature processing condition, making it one of the most widely used polymer hole transport materials inverted perovskite solar cells (PSCs), because of its high optical transparency in the visible light [...] Read more.

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has high optical transparency in the visible light range and low-temperature processing condition, making it one of the most widely used polymer hole transport materials inverted perovskite solar cells (PSCs), because of its high optical transparency in the visible light range and low-temperature processing condition. However, the stability of PSCs based on pristine PEDOT:PSS is far from satisfactory, which is ascribed to the acidic and hygroscopic nature of PEDOT:PSS, and property differences between PEDOT:PSS and perovskite materials, such as conductivity, work function and surface morphology. This review summaries recent efficient strategies to improve the stability of PEDOT:PSS in PSCs and discusses the underlying mechanisms. This review is expected to provide helpful insights for further increasing the stability of PSCs based on commercial PEDOT:PSS. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Perovskite Solar Cells)

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