arXiv subjects

Li-Ming Yang

Publications and source records attributed to Li-Ming Yang.

4 recordsLinked to original sources

arXiv2025

From Disorder to Function: Entropy-Engineered Broadband Photonics with Ion-Transport-Stabilized Spectral Fidelity

The high-entropy halide-perovskite field has expanded rapidly, yet a key gap remains: configurational entropy is not yet a reliable, designable lever to co-deliver expanded photonic functionality and operational robustness with a composition-transferable mechanistic basis. Here we develop entropy-engineered rare-earth halide double-perovskite single crystals, Cs2Na(Sb, RE)Cl6 (RE3+ = Sc3+, Er3+, Yb3+, Tm3+), that simultaneously expand near-infrared (NIR) functionality and establish a mechanistic stability rule. Near-equiatomic B(III)-site alloying yields a single-phase high-entropy solid solution (Delta_Sconfig about 1.6R). Sb3+ serves as a sensitizer that unifies excitation and cooperatively activates multiple lanthanide channels, transforming the parent single-mode response into a broadband NIR output (~850-1600 nm) with three spectrally orthogonal fingerprint bands at 996, 1220, and 1540 nm. This tri-peak, self-referenced output enables redundancy-based ratiometric solvent identification and quantitative mixture sensing with reduced susceptibility to intensity drift. Accelerated aging under humidity and oxygen shows improved phase and emission stability versus single-component analogues. DFT and molecular dynamics attribute the robustness to strongly suppressed RE$^{3+}$/Cl$^-$ self-diffusion despite comparable H$_2$O/O$_2$ adsorption, kinetically impeding ion-migration-assisted reconstruction and degradation. Integration into a phosphor-converted LED delivers spectrally stable, broadband NIR illumination, establishing entropy engineering as a practical handle to couple expanded photonic functionality with mechanistically accountable durability in metal-halide photonics.

physics.optics↗

arXiv2023

Two-dimensional bimetal-embedded expanded phthalocyanine monolayers: a class of multifunctional materials with fascinating properties

The expanded phthalocyanine (EPc) single-layer sheets with double transition metals (labeled as TM2EPc, TM = Sc-Zn) are predicted to be a new class of two-dimensional (2D) metal-organic materials with a series of favorable functional properties by means of systematic first-principle calculations and molecular dynamics simulations. The strong coordination between metal and EPc substrate accounts for the excellent structural stability. Chemical bonding analysis has demonstrated the absence of TM-TM bonding. Each metal center is isolated, but connected to the organic framework by four 2c-2e TM-N {\sigma}-bonds to form an extended 2D network. Unexpectedly, it is found that the V2EPc is an antiferromagnetic metal with Dirac cone, while Cr2EPc exhibits ferromagnetic Dirac half-metallicity, which is not common in 2D materials. Excitingly, the ferromagnetic Cr2EPc and antiferromagnetic Mn2- and Fe2-EPc have high magnetic transition temperatures of 223, 217, and 325 K, respectively, which are crucial for the practical applications of spintronics. Cr2EPc can maintain the Dirac half-metallicity under -6 % ~ 2 % biaxial strains, and Fe2EPc can transform from semiconductor to half-metal by applying -6 % ~ -10 % compressive strains. Additionally, the TM2EPc monolayers exhibit a full response to visible light and some materials have strong absorption in the ultraviolet and infrared regions in addition to visible light, showing extraordinary solar light-harvesting ability. Notably, the designed type-II heterojunctions Fe2EPc/SnC, Co2EPc/GeS, and Ni2EPc/2H-WSe2 have high power conversion efficiency (PCE > 15%), especially the PCE of Ni2EPc/2H-WSe2 reaches 25.19%, which has great potential in solar cell applications. All these desired properties render 2D TM2EPc monolayers promising candidates for future applications in nanoelectronics, spintronics,optoelectronics, and photovoltaic devices.

cond-mat.mtrl-sci↗

arXiv2002

Parton Distribution of Proton in a Simple Statistical Model

Taking proton as an ensemble of quark-gluon Fock states and using the principle of detailed balance, we construct a simple statistical model for parton distribution of proton. The recent observed Bjorken-$x$ dependent light flavor sea quark asymmetry $\bar{d}(x)-\bar{u}(x)$ can be well reproduced by Monte Carlo simulation as a pure statistical effect.

hep-ph↗

arXiv2002

Flavor Asymmetry of Nucleon Sea from Detailed Balance

In this study, the proton is taken as an ensemble of quark-gluon Fock states. Using the principle of detailed balance, we find $\bar{d}-\bar{u} \approx 0.124$, which is in surprisingly agreement with the experimental observation.

hep-ph↗