Article
Instruments & Instrumentation
H. Tajima, A. Okumura, K. Furuta
Summary: Silicon photomultipliers (SiPMs) are replacing photomultiplier tubes in many applications due to their low voltage operations, compactness, and cost efficiency. However, the presence of optical crosstalk (OCT) remains a major drawback, leading to increased accidental triggers and compromised accuracy in photon counting. This study investigates the properties of OCT and delayed OCT in different types of SiPMs, considering device sizes, cell sizes, and resin coating thickness. It is found that delayed OCT exhibits similar characteristics to OCT without resin coating, and a significant portion of delayed OCT overlaps with the original pulse, mimicking OCT when the delay is less than 8 ns. This suggests that the remaining OCTs in SiPMs without coating can be attributed to the overlaps of delayed OCTs.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2023)
Article
Materials Science, Ceramics
Weiwei Cao, Bo Wang, Yang Yang, Bingli Zhu, Junjiang Guo, Peng Xu, Xiaohong Bai, Junjun Qin, Chao Wang, Jingping Zhu, Yonglin Bai
Summary: In this study, an Al2O3/MgO double-layer structure was fabricated as a secondary electron emission layer using ALD technology. Various tests were conducted to evaluate its performance, revealing that the SEY value of the Al2O3/MgO double-layer decreased as the Al2O3 thickness increased, which is beneficial for its application in the channels of microchannel plates.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Applied
Ohhun Kwon, Renjing Huang, Tianyu Cao, John M. Vohs, Raymond J. Gorte
Summary: The study found that LaMnO3 films deposited on MgAl2O4 showed uniform coverage and maintained their structure intact after multiple redox cycles, with Ni also retaining good dispersion. The LaMnO3-supported catalyst exhibited higher activity and superior resistance against coke formation compared to Ni on unmodified MgAl2O4. The performance of Ni on LaMnO3 films was compared to previous results on other oxide films such as LaFeO3, CaTiO3, SrTiO3, and BaTiO3.
Article
Nanoscience & Nanotechnology
Nahid Sultan Al-Mamun, Douglas E. Wolfe, Aman Haque, Jae-Gyun Yim, Seong Keun Kim
Summary: A room temperature annealing method using electron impulse force is demonstrated to significantly improve the crystallinity and reduce the resistivity of tin disulfide, which is important for post-synthesis annealing applications that require high temperature and special environments.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Felix Gayot, Elise Bruhat, Muriel Bouttemy, Mathieu Fregnaux, Eric De Vito, Jean-Paul Kleider, Stephane Cros, Matthieu Manceau
Summary: This study conducted a thorough interface study on the atomic layer deposition (ALD) fabricated tin dioxide (SnO2) electron selective layer (ESL). It was found that ALD-grown SnO2 ESL had limited cell efficiency compared to solution-processed SnO2 ESL. The analysis revealed an unfavorable band bending and a lack of oxygen at the ALD-grown SnO2/perovskite interface, which may be the cause of the observed performance limitations.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Hama Nadhom, Robert Boyd, Polla Rouf, Daniel Lundin, Henrik Pedersen
Summary: The newly developed CVD method allows for area selective deposition based on the electrical resistivity of the substrate surface, simplifying the fabrication of nanoscaled electronics. By adding a thin layer of silver on the SiO2 surface, iron films can be selectively deposited in low-resistivity areas, demonstrating the potential for using electric resistivity of the substrate surface in metal-on-metal deposition.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Applied
Yong Chan Jung, Jin-Hyun Kim, Heber Hernandez-Arriaga, Jaidah Mohan, Su Min Hwang, Dan N. Le, Akshay Sahota, Harrison Sejoon Kim, Kihyun Kim, Rino Choi, Chang-Yong Nam, Daniel Alvarez, Jeffrey Spiegelman, Si Joon Kim, Jiyoung Kim
Summary: This study investigates the robust ferroelectric properties of low-temperature (350 ?) Hf0.5Zr0.5O2 (HZO) films. It is found that the use of anhydrous H2O2 oxidant enables the HZO films to fully crystallize at a lower temperature, with fewer defects. Additionally, this low-temperature crystallization process improves device reliability by suppressing electrode oxidation.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Ningyu Ren, Chengjun Zhu, Renjie Li, Sayantan Mazumdar, Cong Sun, Bingbing Chen, Qiaojing Xu, Pengyang Wang, Biao Shi, Qian Huang, Shengzhi Xu, Tiantian Li, Ying Zhao, Xiaodan Zhang
Summary: Although perovskite solar cells based on SnO2 have achieved high power conversion efficiency, large-scale fabrication remains a challenge. An atomic layer deposition (ALD) process using H2O2 as an oxygen source is demonstrated, enabling low-temperature deposition and producing highly uniform films. This technology shows potential in both single junction and tandem solar cells.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Suresh Thapa, Sydney R. Provence, Patrick T. Gemperline, Bethany E. Matthews, Steven R. Spurgeon, Sydney L. Battles, Steve M. Heald, Marcelo A. Kuroda, Ryan B. Comes
Summary: 4d transition metal oxides, such as SrNbO3, show promise for various applications including high mobility electronics. However, the synthesis of SrNbO3 is challenging due to the metastable nature of the Nb4+ cation and limitations in delivering refractory Nb. In this study, SrNbO3 thin films were successfully grown using hybrid molecular beam epitaxy (MBE) with a Sr source and a tris(diethylamido)(tert-butylimido) niobium precursor. Insulating SrHfO3 capping layers were deposited on top of the SrNbO3 films to preserve the metastable surface. The results demonstrate that the SrHfO3 capping plays a crucial role in preserving the crystalline quality and metastable charge state of Nb4+ under atmospheric conditions.
Article
Chemistry, Physical
Joel Arriaga Davila, Jedrzej P. Winczewski, Manuel Herrera-Zaldivar, Edurado A. Murillo-Bracamontes, Cristian Rosero Arias, Nayely Pineda-Aguilar, Jorge L. Cholula-Diaz, Israel De Leon, Han Gardeniers, Arturo Susarrey Arce, Eduardo Martinez-Gurrera
Summary: This study reports the conformal atomic layer deposition of Al-doped ZnO (AZO) on three-dimensional (3D) shaped ZrO2 microarchitectures produced using two-photon lithography (TPL) for the first time. The influence of ZrO2 morphology, surface roughness, and crystallographic phase on the quality and properties of the deposited ZnO and AZO thin films is investigated. The AZO films exhibit n-type semiconductor behavior and have potential in the production of optoelectronic devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Wei-Hao Lee, Fong-Jyun Jhong, Yu-Tung Yin, Chun-Yi Chou, Jing-Jong Shyue, Miin-Jang Chen
Summary: This paper reports on the significant enhancement of the crystalline quality of nanoscale GaN thin films using a large-area and rapid electron beam annealing technique. The results demonstrate high-quality GaN epilayers with smooth surfaces, indicating potential for various applications.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Nanoscience & Nanotechnology
Tamar Itzhak, Naama Segev-Mark, Assaf Simon, Volker Abetz, Guy Z. Ramon, Tamar Segal-Peretz
Summary: ALD has been found to be an effective technique for growing Al2O3 on polymeric membranes, with control over depth gradient and membrane properties achieved by tuning the exposure time and cycles of Al2O3. The surface modification of Al2O3 was shown to reduce oil droplet coverage on membranes, as revealed by in situ confocal imaging.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Multidisciplinary Sciences
Zheyi Lu, Yang Chen, Weiqi Dang, Lingan Kong, Quanyang Tao, Likuan Ma, Donglin Lu, Liting Liu, Wanying Li, Zhiwei Li, Xiao Liu, Yiliu Wang, Xidong Duan, Lei Liao, Yuan Liu
Summary: A dry dielectric integration strategy enables the transfer of wafer-scale and high-kappa dielectrics on top of 2D semiconductors. An ultra-thin buffer layer is used to pre-deposit sub-3 nm thin Al2O3 or HfO2 dielectrics, which are then mechanically dry-transferred on top of MoS2 monolayers. The transferred ultra-thin dielectric film exhibits wafer-scale flatness and uniformity without any cracks, showing high capacitance, low leakage currents, and excellent transistor properties.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Haifeng Zhang, Ying Ge, Yunkun Lu, Mengjie Yan, Jingcen Zhang, Hao Fu, Haiming Long, Pei Li, Yang Li, Chenzeng Zhang, Junjie Hao
Summary: A reduced-graphene-oxide/Cu (rGO/Cu) composite coating was prepared to suppress the total secondary electron yield. The copper ions were able to enter the graphene oxide (GO) film and nucleate under the applied electric field, resulting in the formation of the composite coating. After heat treatment, the oxygen content of rGO on the surface was reduced, while the carbon content increased. The deposited copper particles sintered and formed chemical bonds, enhancing the bonding strength between the coating and the substrate at high temperatures.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Fuweng Zhang, Kaiqiao Wu, Damiano La Zara, Michael J. Quayle, Feilong Sun, Gunilla Petersson, Staffan Folestad, Jia Wei Chew, J. Ruud van Ommen
Summary: By depositing different materials as nanoscale films onto micronized budesonide powders using atomic/molecular layer deposition (ALD/MLD) coatings, the flow properties of the powders can be altered and improved. Inorganic nanofilms deposited via ALD can reduce inter-particle forces, leading to improved drug delivery performance.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Haibo Xue, Jose Manuel Vicent-Luna, Shuxia Tao, Geert Brocks
Summary: Lattice defects, especially compound defects, significantly affect the stability of halide perovskite solar cells. The most prominent defects in CsPbI3 are the antisite of Pb substituting Cs under equilibrium conditions, while other compound defects are negligible. However, under nonequilibrium thermal and operating conditions, other complexes such as the Cs substituting Pb antisite and compound vacancies of PbI2 or CsPbI3 units become important. These compound defects mainly lead to shallow or inactive charge carrier traps, indicating the electronic stability of halide perovskites.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Zhaotong Qin, Haibo Xue, Minchao Qin, Yuhao Li, Xiao Wu, Wei-Ru Wu, Chun-Jen Su, Geert Brocks, Shuxia Tao, Xinhui Lu
Summary: The influence of two isomeric A'-site ligands on the crystal growth of 2D perovskites was studied, revealing that branched iso-BA(+) facilitates the formation of large clusters and promotes the crystallization of vertically oriented 2D perovskites. Additionally, iso-BA(+) is less likely to be incorporated into the perovskite lattice, suppressing the formation of unwanted multi-oriented perovskites. These findings explain the better performance of 2D perovskite solar cells based on iso-BA(+) and elucidate the fundamental mechanism of ligand structural impact on 2D perovskite crystallization.
Article
Materials Science, Multidisciplinary
Hong-Hua Fang, Eelco K. Tekelenburg, Haibo Xue, Simon Kahmann, Lijun Chen, Sampson Adjokatse, Geert Brocks, Shuxia Tao, Maria Antonietta Loi
Summary: Low-dimensional halide perovskites with broad emission have promising applications as white light sources. This study investigates the origin of the broadband emission in sub-bandgap region of mixed lead-tin 2D perovskite films. The bandgap can be tuned by the lead-tin ratio, while the photoluminescence is broad and fairly insensitive to the relative amount of Pb and Sn. The low-dimensional systems show less bandgap bowing than their 3D counterpart, possibly due to the smaller spin-orbit coupling effect. Time-resolved photoluminescence reveals ultrafast decay in the high-energy range and slower broadband emission decay, indicating defects as the origin of the broadband emission.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Zehua Chen, Haibo Xue, Geert Brocks, Peter A. Bobbert, Shuxia Tao
Summary: The two-dimensional mixed halide perovskite PEA2Pb(I1-xBrx)4 exhibits higher phase stability under illumination compared to the three-dimensional counterpart MAPb(I1-xBrx)3. The improved compositional phase stability is attributed to the preferred I-Br distribution in the 2D perovskite, resulting in a lower critical temperature for halide segregation in the dark. Additionally, the smaller increase of band gap with Br concentration and shorter photocarrier lifetime in the 2D perovskite reduce the driving force for phase segregation under illumination, enhancing the photostability.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Ningyu Ren, Pengyang Wang, Junke Jiang, Renjie Li, Wei Han, Jingjing Liu, Zhao Zhu, Bingbing Chen, Qiaojing Xu, Tiantian Li, Biao Shi, Qian Huang, Dekun Zhang, Sofia Apergi, Geert Brocks, Chenjun Zhu, Shuxia Tao, Ying Zhao, Xiaodan Zhang
Summary: This study demonstrates that by adding a small amount of Cadmium Acetate (CdAc2) in the PbI2 precursor solution, nano-hole array films can be produced, improving the diffusion of organic salts and promoting favorable crystal orientation in perovskite films. This strategy leads to the achievement of high-efficiency flexible perovskite solar cells with a power conversion efficiency (PCE) of 22.78%, and it is also applicable for textured tandem solar cells with a champion PCE of 29.25%. The study provides a facile approach for fabricating high-efficiency perovskite-based solar cells.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jun Xi, Junke Jiang, Herman Duim, Lijun Chen, Jiaxue You, Giuseppe Portale, Shengzhong (Frank) Liu, Shuxia Tao, Maria Antonietta Loi
Summary: This study unravels the mechanism of solvent-catalyzed 2D-3D structural transformation in metal halide perovskites. It is confirmed that protic solvents facilitate the dissociation of formadinium iodide (FAI) through dynamic hydrogen bonding, and the stronger hydrogen bond between phenylethylamine (PEA) cation and solvents promotes the 2D-3D transformation. In the presence of solvents, grain centers transform into 3D phases and grain boundaries transform into quasi-2D phases. This research elucidates the fundamental mechanism of structural transformation in metal halide perovskites, enabling the fabrication of complex heterostructures.
ADVANCED MATERIALS
(2023)
Editorial Material
Multidisciplinary Sciences
Shuxia Tao, Lakshminarayana Polavarapu, Paola Vivo
Summary: In order to be practically used, perovskite solar cells need to address the long-term stability issue. Materials science, using synthetic chemistry, materials characterization, and device engineering, can improve stability and scalability, leading to large-scale production. This Collection showcases recent research efforts in stabilizing perovskite solar cells, focusing on characterizing instability, synthesizing stable perovskites, and improving interfaces.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
Xin Zhang, Weiming Qiu, Sofia Apergi, Shivam Singh, Paulo Marchezi, Wenya Song, Christian Sternemann, Karim Elkhouly, Dong Zhang, Aranzazu Aguirre, Tamara Merckx, Anurag Krishna, Yuanyuan Shi, Andrea Bracesco, Cristian van Helvoirt, Frennie Bens, Valerio Zardetto, Jan D'Haen, Anran Yu, Geert Brocks, Tom Aernouts, Ellen Moons, Shuxia Tao, Yiqiang Zhan, Yinghuan Kuang, Jef Poortmans
Summary: Inverted p-i-n perovskite solar cells have potential for commercialization, but the interfaces with charge transport layers cause major power conversion efficiency (PCE) loss and instability. By using 2-thiopheneethylammonium chloride (TEACl), we molecularly engineer both interfaces and achieve optimized band alignment, suppressed nonradiative recombination, and improved interfacial contact. The resulting solar cells demonstrate a PCE of 24.3% and good performance retention after 1000 hours of illumination.
ACS ENERGY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Andrea E. A. Bracesco, Jarvi W. P. Jansen, Haibo Xue, Valerio Zardetto, Geert Brocks, Wilhelmus M. M. Kessels, Shuxia Tao, Mariadriana Creatore
Summary: By optimizing the optoelectronic properties of the absorber and its interfaces with charge transport layers (CTLs), perovskite photovoltaics has achieved conversion efficiencies of 26.0%. However, commonly adopted organic CTLs can cause parasitic absorption and device instability, so metal oxides like atomic layer-deposited SnO2 have been introduced for enhanced stability. When ALD SnO2 is directly processed on the absorber without the fullerene layer, chemical modifications of the inorganic fraction of the perovskite occur, compromising the device performance.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Mriganka Singh, Maged Abdelsamie, Qihua Li, Tim Kodalle, Do-Kyoung Lee, Simon Arnold, Davide R. Ceratti, Jonathan L. Slack, Craig P. Schwartz, Christoph J. Brabec, Shuxia Tao, Carolin M. Sutter-Fella
Summary: This study investigates the formation of triple cation, mixed halide perovskite compositions and the effects of solvents and antisolvents during crystallization. The results show that different solvents and antisolvents have significant influences on the morphology and crystallization pathways of perovskite.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jinqiu Liu, Chao Zhu, Mike Pols, Zhen Zhang, Fengrui Hu, Lin Wang, Chunfeng Zhang, Zheng Liu, Shuxia Tao, Min Xiao, Xiaoyong Wang
Summary: Understanding the structure-property relationships in semiconductor mixed-halide perovskites is crucial for their potential applications in optoelectronic devices. In this study, RP plane stacking faults were formed during the crystal growth of CsPbBr1.2I1.8 nanocrystals, resulting in the presence of multiple nanodomains with discrete mixed-halide compositions. The photoluminescence peaks from these nanodomains can be resolved simultaneously at cryogenic temperature, indicating the interactions of coupled quantum dots within a single nanocrystal.
Article
Chemistry, Physical
Zhiwen Zhou, Qihua Li, Mojun Chen, Xuerong Zheng, Xiao Wu, Xinhui Lu, Shuxia Tao, Ni Zhao
Summary: In this study, a strategy of additive engineering was used to improve the stability and performance of field-effect transistors (FETs) based on 3D formamidinium tin iodide (FASnI(3)) films. By studying the effects of different additives, it was discovered that phenethyl-ammonium (PEA) and its fluorinated derivative (FPEA) can enhance the crystallization of FASnI(3) films and reduce structural defects. The optimized FPEA-modified FASnI(3) FETs showed record high field-effect mobility and excellent stability.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Zhaotong Qin, Mike Pols, Minchao Qin, Jianquan Zhang, He Yan, Shuxia Tao, Xinhui Lu
Summary: By optimizing the crystal orientation through a regulation of the Pb/Sn ratio, we achieved a record high efficiency of 18.06% for quasi-two-dimensional (2D) Pb-Sn mixed perovskite solar cells. Increasing the Pb content can suppress the unwanted horizontal 2D phase and enhance the growth of vertical 2D phases, leading to improved device performance and stability.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Mike Pols, Victor Brouwers, Sofia Calero, Shuxia Tao
Summary: Machine-learned force fields, trained with an active learning scheme against accurate density functional theory calculations, allow us to investigate defect migration in halide perovskites. We find that halide interstitials migrate faster than halide vacancies, with interstitials having shorter migration paths. Both types of defects migrate faster in CsPbI3 than in CsPbBr3, attributed to the less compact packing of ions in CsPbI3 leading to more frequent defect migration jumps.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Qihua Li, Silvia Gaastra-Nedea, David Smeulders, Shuxia Tao
Summary: Defects, oxygen species, and local charges play important roles in the long-term stability of CH3NH3PbI3 perovskites, but their complex interplay and atomistic degradation mechanisms are not well-understood. Using density functional theory calculations and chemical bonding analysis, we investigate the effect of oxygen and local charges on perovskite degradation. We find that oxygen facilitates the formation of iodine vacancies and excess electrons accelerate the degradation via peroxide formation. The peroxide disintegrates the perovskite lattice on surfaces and induces a cascade of degradation reactions, ultimately leading to lattice destruction. We demonstrate that the addition of holes can prevent peroxide formation and potentially improve perovskite stability.
