Article
Chemistry, Multidisciplinary
Mengxia Liu, Sachin Dev Verma, Zhilong Zhang, Jooyoung Sung, Akshay Rao
Summary: This study reports the direct visualization of carrier propagation in PbS CQD solids and quantum-dot-in-perovskite heterostructures, revealing three distinct transport regimes. By tailoring the perovskite content in heterostructures, the researchers were able to achieve a superdiffusive transport length exceeding 90 nm at room temperature and up to 106 cm(2) s(-1) diffusivity, introducing promising strategies to harness nonequilibrium transport phenomena for more efficient optoelectronic devices.
Article
Chemistry, Physical
Shanshan Ding, Julian A. Steele, Peng Chen, Tongen Lin, Dongxu He, Chengxi Zhang, Xiangqian Fan, Eduardo Solano, Andrew K. Whittaker, Mengmeng Hao, Lianzhou Wang
Summary: This study demonstrates the surface passivation of formamidinium lead iodide quantum dots (QDs) by introducing tailored multifunctional ligands (glycocyamine (GLA)), leading to improved energy band alignment and enhanced device performance. The use of GLA ligands reduces non-radiative recombination loss and promotes favorable charge transport. This results in a record-high power conversion efficiency (PCE) of 15.34% and improved device stability.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Lingyu Meng, Junhao Peng, Huafeng Dong, Minru Wen, Fugen Wu
Summary: 2D PtSe2/HfS2 heterostructures show potential for application in infrared photodetectors, overcoming limitations of 2D PtSe2 photodetectors. The vertical structures exhibit type-II band alignment and a smaller bandgap, while different stacking configurations do not change the type of band alignment and have similar bandgaps.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Eunjung Ko, Jung-Hae Choi
Summary: This study investigates the effects of interface atomic rearrangement on the band alignments of Ge/a-Al2O3/Au structures using first principles calculations. Results show that significant atomic rearrangement at the interface regions leads to a slanted band alignment in the oxide region, which cannot be explained by existing numerical models. The band alignment is explained by considering the interface dipoles caused by changes in the interface work function and the interface effective charge density, dismissing the previously overlooked importance of these factors.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Taek Joon Kim, Sang-hun Lee, Eunji Lee, Changwon Seo, Jeongyong Kim, Jinsoo Joo
Summary: In this study, the energy band alignments of a heterostructure consisting of MAPbI(3) perovskite sheets and CdSe-ZnS core-shell quantum dot layers were modulated, leading to the emission of far-red interlayer excitons. These excitons exhibited a longer lifetime and strong dipole alignment at the heterojunction. An abnormal behavior of the optical characteristics near the phase transition temperature of MAPbI(3) was observed. Photodetectors based on MAPbI(3)/CdSe-ZnS-QD heterostructures showed increased photocurrent and detectivity compared to MAPbI(3) under interlayer exciton excitation.
Article
Chemistry, Physical
Guangjing Hou, Yatao Pan, Lulu Qiao, Xia Ran, Tianfeng Li, Zhen Chi, Pingan Liu, Yulu He, Yanmin Kuang, Lijun Guo
Summary: This study demonstrates the enhanced photoelectric properties of Au nanoclusters (Au NCs) and graphene quantum dots (GQDs) composites. The Au NCs act as electron donors to sensitize the GQDs, resulting in improved light absorption and photoelectric performance. The efficient electron transfer from Au NCs to GQDs quenches the fluorescence of Au NCs and enhances the charge separation. The type-II band alignment of Au NCs and GQDs promotes the electron transfer and enhances the photoelectric current.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Ying Wang, Mengjie He, Chenhai Shen, Jianye Wang, Congxin Xia
Summary: In this study, we constructed two-dimensional Janus SnSSe/phosphorene van der Waals heterostructures and investigated the effects of external factors on their electronic properties. The results revealed that different interface patterns can result in type III and type II heterostructures. Within a certain range, weakened interlayer coupling or in-plane tensile strain can transform Se-interface heterostructures from intrinsic type II to type III, while S-interface heterostructures remain robust. Additionally, a positive electric field can adjust the heterostructures to exhibit type II, type III, or type I characteristics, while a reverse electric field can only expand the tunneling window of type III heterostructures. This work suggests that interface-modified Janus SnSSe/phosphorene van der Waals heterostructures have potential applications in optoelectronics and tunneling FETs.
RESULTS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Huizi Tang-Wang, Chuan Zhou, Ying Wang, Yingnan Guo, Shufang Wang, Guangsheng Fu, Baolai Liang, Yuriy I. Mazur, Morgan E. Ware, Gregory J. Salamo
Summary: In this study, InAs(Sb)/GaAs self-assembled quantum dots (QDs) with type II band alignment were successfully grown by incorporating Sb into InAs and increasing the beam equivalent pressure ratio. These InAsSb QDs exhibit different characteristics compared to the well-studied type-I InAs QDs in terms of excitation intensity, temperature dependence, and luminescence time dependence. The Sb distribution in the QDs and the wetting layer was also investigated.
Article
Chemistry, Physical
Jian Ni, Jiayi Guan, Minghao Hu, Rufeng Wang, Zhiwei Yang, Jun Li, Shuai Zhang, Sen Li, Juan Li, Hongkun Cai, Jianjun Zhang
Summary: Inorganic CsPbBr3 perovskite solar cells have attracted attention for their low cost and resistance to environmental factors. However, the crystallization mechanism and valence band offset limitations hinder efficiency improvement. By optimizing the crystallization process and using quantum dots for modification, higher efficiencies and stability can be achieved.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Physics, Applied
S. L. Benz, M. Becker, A. Polity, S. Chatterjee, P. J. Klar
Summary: The combination of copper oxides with gallium sesquioxide is considered an excellent heterojunction system for overcoming challenges in solar cell applications. Among the studied heterostructures, the Cu2O/α-Ga2O3 heterostructure appears to offer the most favorable band alignment for photovoltaic applications within the experimental margin of error.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Energy & Fuels
Long Liu, Bing Bai, Jun Li, Yi Zhou, Hsien-Yi Hsu, Guohua Jia
Summary: This article provides an overview of the potential applications of heterostructure nanocrystals in various fields, including lighting devices, lasers, photocatalysis, and biological applications. By tuning the band alignment, the properties of these nanocrystals can be modified.
Article
Energy & Fuels
Meiying Li, Shuaipu Zang, Yinglin Wang, Jinhuan Li, Jiangang Ma, Xintong Zhang, Yichun Liu
Summary: This study successfully improved the power conversion efficiency of PbS colloidal quantum dot solar cells by preparing a n(+)−n double-layered ZnO electron transport layer.
Article
Chemistry, Physical
Jinpeng Huo, Guisheng Zou, Yu Xiao, Tianming Sun, Bin Feng, Daozhi Shen, Chengjie Du, Jin Peng, Luchan Lin, Lei Liu
Summary: In this study, a novel strategy for tailoring the band alignment of BP/MoS2 heterostructures using femtosecond laser-controlled band alignment engineering is demonstrated. Although this approach compromises the rectification ratio of heterostructures, it dramatically expands the tuning range of the band alignment and improves optoelectronic response. Additionally, a new physical model is proposed to describe carrier transport behavior for m-n-p structures and the effect of femtosecond laser irradiation is investigated. Two conceptual devices are also demonstrated to show the advanced applications of this post-processing technique.
Article
Nanoscience & Nanotechnology
Qingfang Li, Qiqi Li, Yongping Du, Lei Zhang, Hongzhe Pan, Haifeng Wang
Summary: The successful fabrication of lateral heterostructures (LHSs) integrating monolayer C3N and C3B along different directions has led to the discovery of excellent stability and electronic properties. The band structures of (C3N)2(C3B)2 LHSs undergo transitions from indirect to direct, and the tensile strain can effectively modulate the band structures, with the zigzag-(C3N)2(C3B)2 band being reversed under strain.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Biochemical Research Methods
Teymour Talha-Dean, Kai Chen, Giulia Mastroianni, Felice Gesuele, Jan Mol, Matteo Palma
Summary: In this study, a strategy to control the assembly of heterostructures and tune their electronic coupling employing DNA as a linker was reported. MoS2 nanosheets were functionalized with biotin-terminated dsDNA using different chemical strategies, and streptavidinated quantum dots were tethered to the DNA-functionalized MoS2 surface. Nanoscale control over the separation between the two nanostructures was achieved by varying the number of base pairs constituting the DNA linker. Spectroscopic data confirmed the successful functionalization and demonstrated the electronic coupling between the two nanostructures.
BIOCONJUGATE CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Stefan Seritan, Yuanheng Wang, Jason E. Ford, Alessio Valentini, Tom Gold, Todd J. Martinez
Summary: Interactive molecular dynamics in virtual reality (IMD-VR) simulations provide a digital molecular playground for students, while InteraChem molecular visualizer allows for reactive simulations using semiempirical and ab initio methods, with added features like speech recognition and emojis to indicate energetic feasibility of bonding arrangements.
JOURNAL OF CHEMICAL EDUCATION
(2021)
Article
Chemistry, Multidisciplinary
Thomas C. Rossi, Conner P. Dykstra, Tyler N. Haddock, Rachel Wallick, John H. Burke, Cecilia M. Gentle, Gilles Doumy, Anne Marie March, Renske M. van der Veen
Summary: Understanding the electronic structure and dynamics of semiconducting nanomaterials at the atomic level is crucial for optimizing devices in solar energy, catalysis, and optoelectronic applications. The study using ultrafast X-ray linear dichroism spectroscopy reveals a depletion of absorption cross sections in transient X-ray spectra due to photogenerated charge carriers screening the core-hole potential of the X-ray absorbing atom, paving the way for future research on charge transfer dynamics across heterostructured interfaces.
Article
Chemistry, Physical
Yuanheng Wang, Stefan Seritan, Dean Lahana, Jason E. Ford, Alessio Valentini, Edward G. Hohenstein, Todd J. Martinez
Summary: INTERACHEM is an interactive molecular dynamics (AI-IMD) visualizer that utilizes virtual reality hardware and graphical processing unit (GPU) acceleration to render quantum chemistry in real time. It allows exploration of electronically excited states and real-time tracking of electronic properties such as molecular orbitals and bond order. This tool aids in the interpretation of excited state chemistry data and makes quantum chemistry more accessible for research and education.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Physics, Multidisciplinary
Omid Zandi, Renske M. van der Veen
Summary: This study presents a theoretical approach to studying the dynamics of different charge distributions under their self-electric fields and stochastic forces. The approach is based on the charge-current continuity equation and drift velocities of particles. By applying kinetic theory, the study includes the stochastic force due to random motions of electrons and compares the results with simulations.
JOURNAL OF PHYSICS COMMUNICATIONS
(2022)
Review
Chemistry, Multidisciplinary
Francis M. M. Alcorn, Prashant K. K. Jain, Renske M. M. van der Veen
Summary: The ability of transmission electron microscopy (TEM) to image structures ranging from millimetres to angstroms has made it an indispensable tool for modern chemists. Recent developments in TEM have allowed for real-time probing of structural evolution on the nanoscale. Time-resolved in situ TEM techniques are discussed in this review, along with their applications for studying chemical and physical processes.
NATURE REVIEWS CHEMISTRY
(2023)
Article
Chemistry, Physical
Francis M. Alcorn, Maya Chattoraj, Renske M. van der Veen, Prashant K. Jain
Summary: Using a transmission electron microscope with laser excitation, we observed Ostwald ripening of Au-Cu alloy nanoparticles under plasmonic excitation. This structural transformation, distinct from electron-beam-induced coalescence, is not thermally induced but instead triggered by plasmonically excited carriers.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Francis M. Alcorn, Renske M. van der Veen, Prashant K. Jain
Summary: Researchers used a high-resolution transmission electron microscope to observe the structural evolution of Cu-based nanoparticles under electron beam irradiation and plasmonic excitation. They found that these particles undergo hollowing via the nanoscale Kirkendall effect. Hollowing is triggered by electron beam irradiation, and plasmonic excitation enhances the kinetics of the transformation, likely through the effect of photothermal heating.