The Journal of Physical Chemistry C最新文献

{"title":"Origin of the Indirect–Direct Band Gap Transition in GaP and Its Alloys","authors":"Yatian Ning, Man Wang, Xubo Jia, Honggang Ye, Jinying Yu, Yelong Wu","doi":"10.1021/acs.jpcc.4c08736","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08736","url":null,"abstract":"Indirect GaP-based photoelectric devices often exhibit low photoelectric conversion efficiencies. Numerous research efforts have been undertaken to facilitate indirect–direct transitions; however, a comprehensive understanding of the nature of these transitions remains elusive. In this study, we demonstrate that the occupied d orbitals, strain, and electronegativity are the three critical factors influencing the indirect–direct transition in GaP. Elevating the occupied d orbitals can raise the conduction band <i>X</i> and <i>L</i> valleys through s–d and p–d coupling while leaving the Γ valley unchanged, thereby facilitating the transition. The <i>X</i> valley possesses positive deformation potentials, whereas the Γ and <i>L</i> valleys exhibit negative ones. Consequently, a mere 0.6% tensile strain can convert the GaP band gap from indirect to direct. Additionally, larger electronegativity anions can lower the conduction band Γ valley via s–s coupling, further triggering the transition. Further investigation into the mechanisms at play in GaP alloys reveals that strain is the most sensitive factor and is crucial under most conditions. Based on these underlying mechanisms, we propose new alloys such as (GaP)_1–<i>x</i>(ZnO)_<i>x</i> and (GaP)_1–<i>x</i>(ZnS)_<i>x</i>. This work provides a framework for analyzing semiconductor indirect–direct transitions and offers insights for designing photoelectric devices based on indirect band gap semiconductors.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"70 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergy for Enhancing Strength and Toughness of Diamond through Polytypic Heterointerface","authors":"Tengfei Xu, Zhaorui Liu, Dominik Legut, Ruifeng Zhang","doi":"10.1021/acs.jpcc.5c00702","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00702","url":null,"abstract":"Hierarchical diamond nanocomposites, incorporating diverse coherently interfaced diamond polytypes, exhibit remarkable fracture toughness while maintaining exceptional hardness. However, the underlying mechanisms governing the strengthening and toughening of these polytypic heterointerfaces (PHIs) remain elusive. In this study, we employed first-principles approaches to derive the ideal strength and Peierls stress, conducting a comprehensive investigation into the influence of various PHIs on the plasticity of nanostructured diamond. A ubiquitous strengthening effect was observed across all PHI types under uniform shear deformation, as the introduction of PHIs invariably aligned a portion of the crystal in the hard shear direction, yielding strength comparable to that of the nanotwinned diamond. Surprisingly, graphitization and bond collapse were suppressed through a sequential transformation of stacking sequences, including an experimentally observed non-3C to 3C polytype transition. This phenomenon was attributed to the systematic bond realignment driven by continuous metallization confined to specific atomic layers. The heterointerface-mediated bonding reorganization effectively dissipated energy through phase transitions, thereby achieving supertoughness. Under localized deformation, all PHIs were found to enhance the barrier against parallel slip of 1/2 ⟨110⟩ shuffle-set full dislocations and 1/6 ⟨112⟩ glide-set partial dislocations, leading to a pronounced strengthening effect. These findings not only deepen our fundamental understanding of the synergistic strengthening and toughening of diamond through PHIs but also offer valuable insights for the design of other superhard materials and engineering ceramics via coherent heterointerfaces.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"36 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shell Composition-Mediated Band Alignment and Defect Engineering in Indium Phosphide-Based Core/Shell Quantum Dots","authors":"Qinggang Hou, Yixiao Huang, Jiahua Kong, Ruiling Zhang, Aleksandr A. Sergeev, Zhannan Peng, Zhenhua Sun, Jianguo Tang, Andrey L. Rogach, Zhonglin Du","doi":"10.1021/acs.jpcc.5c01061","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01061","url":null,"abstract":"Realization of a suitable energy band structure of core–shell-structured indium phosphide (InP)-based quantum dots (QDs) is crucial for their anticipated use in various optoelectronic devices. In this study, we demonstrate how to achieve the optimal band alignment and defect engineering of InP core/Zn_1–<i>x</i>Cd_<i>x</i>Se shell QDs by systematically varying the shell composition. Using advanced spectroscopic techniques, we show how the alloyed Zn_1–<i>x</i>Cd_<i>x</i>Se shell reduces surface defects while simultaneously tuning the charge carrier wave functions from localization to delocalization mode due to the band alignment shift from type-I to quasi-type-II. These InP-based core/shell QDs also exhibit outstanding stability under high-energy ultraviolet irradiation and thermal treatment, as well as long-term storage stability, which is essential for device applications. Furthermore, studies using floating gate transistors based on InP-based core/shell QDs demonstrate the synergistic influence of the energy band structure and defects on charge injection and the spontaneous recovery of the trapped charges.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"18 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Substrate Roughness on the Thermal Boundary Conductance in 2D Materials","authors":"Sylvester W. Makumi, Zlatan Aksamija","doi":"10.1021/acs.jpcc.4c08172","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08172","url":null,"abstract":"Heat dissipation and thermal management are key challenges for further adopting two-dimensional (2D) materials in nanoelectronics. Due to their large aspect ratio, most heat removal is through the substrate. Atomic-scale roughness at the surface of the substrate, together with the mechanical properties and the adhesion of 2D materials to the substrate, dictates how well 2D sheets conform and transfer heat to the substrate. However, a complete understanding of the combined impact of these factors on the thermal boundary conductance (TBC) of 2D/substrate interfaces is lacking. Here, we have used a numerical model to explore the TBC of interfaces between single layers of graphene, hBN, and MoS₂ and rough a-SiO₂ substrate. Our study shows that the effect of roughness on TBC depends on the average surface slope, defined as the ratio of rms roughness height and correlation length (Δ_rms/<i>L</i>_cor), rather than Δ_rms alone. We find that 2D materials conform well to a rough substrate when the surface slope is small and that the effective TBC remains unchanged. However, steep surface slope (Δ_rms/<i>L</i>_cor &gt; 0.1), caused by large roughness or short lateral correlation length, makes the 2D material partially delaminate from the substrate, leading to variations in van der Waals (vdW) spring coupling constant (<i>K</i>_s). For interfaces with weak adhesion, outlier <i>K</i>_s values lead to an enhancement in the effective TBC by up to 12% compared to that of a flat interface, provided the in-plane thermal conductivity of the 2D sheet is sufficient (&gt;1 Wm^1– K^–1) to spread the heat effectively. For interfaces with strong adhesion, we show that it is necessary that the slope remains below 0.1. Beyond this, the 2D material gets delaminated and coupling is weakened, resulting in a lower effective TBC. Therefore, our work provides essential information that will contribute to designing electronic devices with more efficient thermal management.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"1 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Mechanism and Productivity of Single-Pulse Laser Fragmentation of Organic Curcumin Dispersions in a Continuous Flat Jet Flow-Through Reactor","authors":"Tina Friedenauer, Maximilian Spellauge, Alexander Sommereyns, Christoph Rehbock, Heinz P. Huber, Stephan Barcikowski","doi":"10.1021/acs.jpcc.4c08643","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08643","url":null,"abstract":"Curcumin is a natural food additive (nutraceutical), whose bioavailability is impaired by low solubility, a drawback which may be overcome by particle size reduction. Microparticle (MP) laser fragmentation in liquids (LFL) is an emerging production method for sensitive, organic submicron particles (SMPs) and nanoparticles (NPs), as it is characterized by processing at minimal chemical degradation. However, the fragmentation mechanisms need to be understood to tune the MP-LFL process toward a high SMP yield. Therefore, we used pump-probe microscopy (PPM) to elucidate the dynamics of shockwave formation and cavitation bubble growth on single-curcumin particles in correlation with laser fluence utilizing a ps-pulsed laser at 1040 nm. We observed LFL to occur at a threshold fluence of 60 mJ cm^–2. Furthermore, we found a pressure buildup of 308 MPa within the particle, which exceeds the material’s tensile strength by one order of magnitude, hinting at strong contributions of photomechanical effects during curcumin MP-LFL. Consecutively, we examined the transfer to MP dispersions where concentration effects during MP-LFL were studied using a ps-pulsed laser at 532 nm and an optimized continuous flat jet (FJ) reactor, which is characterized by the ability to process particularly high concentrations of up to 1000 mg L^–1 due to the low liquid layer thickness. An increased mass yield of SMP and NP (determined by UV–vis extinction spectroscopy and SEM) was found at high educt concentrations of 500 mg L^–1, which leads to a relative SMP mass yield of 62% and a productivity of 278 mg h^–1, with the potential for quantitative conversion of all MPs into SMPs at optimized illumination conditions (100% yield, 500 mg h^–1). The outstandingly low by-product fraction (&lt; 0.5%) by far surpasses the standard comminution processes applied today, rendering the MP-LFL technology even more relevant to the food or pharma sector.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"90 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear Metasurfaces: A New Paradigm for Short-Wavelength Generation and Modulation","authors":"Zhihui Wang, Rong Lin, Chen Chen, Jiajun Wu, Jin Yao, Din Ping Tsai","doi":"10.1021/acs.jpcc.5c01186","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01186","url":null,"abstract":"Ultraviolet (UV) light has a shorter wavelength and higher photon energy, making it critical for numerous applications such as spectroscopy, microscopy, and information processing. Compared with conventional approaches, nonlinear metasurfaces offer a compact and flexible platform for UV light generation and manipulation. They leverage the strong light–matter interactions and resonant effects to efficiently convert fundamental light into the UV region. In this perspective, we reveal the underlying principles of UV generation based on nonlinear metasurfaces and review the latest advances in ultraviolet light generation and manipulation by plasmonic and dielectric nonlinear metasurfaces. Finally, we discuss the current challenges and future directions. We believe that nonlinear metasurfaces hold great potential for advancing UV photonics.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"98 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Circular Dichroism of Chiral Quantum Rods","authors":"Rui Sun, Bolin Feng, Xiaoqing Gao","doi":"10.1021/acs.jpcc.4c08802","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08802","url":null,"abstract":"Circular dichroism (CD) and magnetic circular dichroism (MCD) are two distinct spectroscopic techniques that offer valuable insights into the properties of materials. Generally speaking, CD spectroscopy reveals information about the ground electronic states of chiral materials, while MCD spectroscopy is sensitive to the degeneracy splitting of energy states in achiral materials under an applied magnetic field. For typical chiral molecules, the measurement of their MCD spectra invariably involves an intrinsic CD signal, which arises from their chiral structure. Consequently, the MCD spectrum can be dissected into two components: one is the CD spectrum arising from the asymmetry of the geometric structure inherent to the chiral molecules; the other is the MCD spectrum associated with the corresponding racemic mixtures. This principle of spectral decomposition is well-established in molecular systems; however, a natural question arises: what is the situation like in inorganic nanosystems? To address this query, an in-depth analysis was conducted of the MCD spectra of chiral quantum rods (QRs) with the same diameter but varying lengths. Intriguingly, it was discovered that the analytical approach applicable to chiral molecules can also be extended to chiral quantum rods (QRs), especially when chiral molecules are present on the surfaces of these materials. This finding holds great significance, as it paves the way for a more accurate and comprehensive MCD analysis of inorganic nanoparticles, potentially enabling new insights and applications in nanomaterials research.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"4 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phonon Dissipation of Atomic-Scale Fatigue in Phosphorene with Zigzag and Armchair Directions","authors":"Yun Dong, Jinguang Wang, Yi Tao, Futian Yang, Xinyi Tang, Bo Shi, Yifan Liu","doi":"10.1021/acs.jpcc.5c01158","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01158","url":null,"abstract":"Herein, we explore the low-cycle fatigue properties of phosphorene in the zigzag and armchair directions as well as their phonon energy dissipation. The results indicate that the armchair direction of phosphorene possesses a fatigue life higher than that of the zigzag direction. Moreover, the fatigue life is negatively correlated with both excitation frequency and excitation amplitude. The phenomenon of stress accumulation occurs during the fatigue process until the interatomic bonds break to produce cracks. In addition, the stress accumulation efficiency rises as the excitation frequency increases, and the fatigue life is lower. As the excitation frequency and excitation amplitude increase, the number of in-plane acoustic modes increases, generating new energy dissipation channels; more energy-carrying phonons are excited, which ultimately leads to higher energy dissipation efficiency and therefore lower fatigue life.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"28 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical Mechanics Model of Interacting Asymmetric Polyatomic Species: Application to the Adsorption of para-Aminobenzoic Acid on a V2O5 Surface","authors":"Antonio José Ramirez-Pastor, José Luis Riccardo, Fabian Dietrich","doi":"10.1021/acs.jpcc.5c00091","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00091","url":null,"abstract":"Vanadium pentoxide (V₂O₅) holds significant potential for technological applications in lithium-ion battery. The efficiency and lifespan of these batteries during charging cycles can be enhanced by cathode passivation, for example, using a self-assembled layer of para-aminobenzoic acid (pABA). In this study, the adsorption of pABA on the V₂O₅ surface was investigated using density functional theory (DFT) calculations. These calculations examined the pABA-surface and pABA–pABA interactions in various adsorption configurations, including molecules in both the first and second adsorption layers. Additionally, a nonideal lattice gas model combined with a statistical mechanics inhomogeneous mean-field approximation, was developed to account for the polyatomic nature of pABA, its asymmetric linear structure, and nearest-neighbor interactions in different adsorption configurations. The partial and overall adsorption isotherms were derived based on the interaction parameters obtained from DFT calculations. The findings reveal that a double-layer, flat configuration predominates at surface saturation, which is consistent with previously reported angle-resolved XPS measurements.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"4 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giant Three-Photon and Four-Photon Absorption in Hybrid MAPbBr3 and FAPbBr3 Perovskite Nanocrystals","authors":"Dipanjan Banerjee, Somnath Das, Anunay Samanta, Gopala Krishna Podagatlapalli, Venugopal Rao Soma","doi":"10.1021/acs.jpcc.5c01215","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c01215","url":null,"abstract":"We have investigated the peak intensity and wavelength-dependent optical nonlinear (NLO) behavior of the nanocrystalline (NC) bromide perovskites (MAPbBr₃ and FAPbBr₃) dispersed in <i>n</i>-hexane via the single-beam femtosecond Z-scan technique. The average edge dimensions of the bromide perovskite NCs estimated from the transmission electron microscope were 12.1 ± 1.1 and 14.3 ± 0.8 nm for the MAPbBr₃ and FAPbBr₃ NCs. At the same time, their excitonic peaks appear at 508 and 516 nm with bright photoluminescence emissions at 519 and 529 nm, respectively. Our intensity-dependent Z-scan studies (with ∼50 fs pulses) on FAPbBr₃ NCs have demonstrated an interesting reverse saturable absorption (RSA) in SA behavior with two-photon absorption coefficients (β) of ∼10^–11 cm/W. On the other hand, the MAPbBr₃ NCs exhibited such RSA in SA at lower peak intensities (32, 43, and 54 GW/cm²) and a pure RSA with strong three-photon absorption coefficients (γ) at higher intensities (65, 76, and 87 GW/cm²). In contrast, the wavelength-dependent studies on the NCs with input wavelengths of 1000, 1100, and 1200 nm (∼70 fs, 1 kHz pulses) at a peak intensity of ∼65 GW/cm² exhibited only RSA behavior with strong four-photon absorption coefficients (δ) of ∼ 10^–32 cm⁵/W³. All other characteristic NLO coefficients involving these hybrid NCs, including intensity-dependent refractive indices (<i>n</i>₂), two- and three-photon absorption cross sections (σ₂ and σ₃, respectively), further unveil their promising utility in optoelectronic and related NLO applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"72 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}