Low Work Function Research Articles

Growth of Atomic layer-deposited Monoclinic Molybdenum Dioxide Films Stabilized by Tin Oxide Doping for DRAM Capacitor Electrode Applications.

Dynamic random-access memory (DRAM) capacitor electrodes, exemplified by TiN, face performance limitations owing to their relatively low work functions in addition to the formation of a low-k interfacial layer caused by their insufficient chemical stability. With recent advances in device scaling, these issues have become increasingly problematic, prompting the exploration of alternative electrode materials to replace TiN. Molybdenum dioxide (MoO2) has emerged as a promising candidate for this application, outperforming TiN due to its low resistivity, high work function (>5 eV), and excellent chemical stability. Moreover, monoclinic MoO2 exhibits a distorted rutile structure, enabling the in situ growth of high-k rutile TiO2 on MoO2 at low deposition temperatures. However, MoO2 deposition poses challenges because of its metastable nature compared to the more stable molybdenum oxide (MoOx) phases, such as MoO3 and Mo4O11. In this work, we successfully fabricated Sn-doped MoOx (TMO) films by atomic layer deposition (ALD) at 300 °C. A stabilized monoclinic MoO2 phase was achieved using ALD by incorporating SnOx into MoOx on both SiO2 and TiN substrates. The ALD TMO process comprised MoOx and SnOx subcycles, and the MoOx:SnOx subcycle ratio was varied from 100:1 to 20:1. High growth rates ranging from 0.19 to 0.34 nm/cycle were achieved for ALD TMO with varying the MoOx:SnOx subcycle ratio from 20:1 to 100:0. After post-deposition annealing at 500 °C, polycrystalline TMO films were obtained with smooth surface morphology. ALD TMO exhibited excellent interface quality with ALD TiO2, possessing a negligible low-k interfacial layer. Moreover, a rutile TiO2 film with a high dielectric constant of 136 was successfully grown on a 20% Sn-TMO electrode. Overall, this study provides a strategy to stabilize metastable MoO2 films using ALD, and it demonstrates the superiority of ALD TMO as a promising DRAM capacitor electrode material.

Electride pure α-Zr: interstitial electrons induced type-II nodal line

Electrides have attracted significant attention in the fields of physics, materials science, and chemistry due to their distinctive electron properties characterized by weak nuclear binding. In this study, based on first-principles calculations and symmetry analysis, we report that the pure zirconium with alpha-phase (α-Zr) is expected to be the electrically neutral electride with topological nodal loop. Furthermore, the nodal loop located at the kz = 0 plane exhibits a clear drumhead-like surface state. The energy levels of the topological nodal loop can be regulated by applying uniaxial strain, resulting in the topological nodal loop being closer to the Fermi level. Remarkably, the work function of the electride Zr shows a significant anisotropy along the (001), (100), and (110) directions, particularly with a low work function of 3.14 eV along the (110) surface. Therefore, we predict that α-Zr provides a promising platform for future research on topological electrides.

Low turn-on voltage and 2.3 kV β -Ga2O3 heterojunction barrier Schottky diodes with Mo anode

In this work, we propose combining a low work function anode metal and junction barrier Schottky structure to simultaneously achieve low turn-on voltage (Von) and high breakdown voltage (BV), which alleviates the dilemma that high BV requires high Schottky barrier height (SBH) and high Von. Molybdenum (Mo) is used to serve as the anode metal to reduce the SBH and facilitate fast turn-on to achieve a low Von. To resolve the low SBH related low BV issue, a p-NiO/n-Ga2O3-based heterojunction structure is used to enhance β-Ga2O3 sidewall depletion during the reverse state to improve the BV. With such a design, a low Von = 0.64 V(@1A/cm2) and a high BV = 2.34 kV as well as a specific on-resistance (Ron,sp) of 5.3 mΩ cm2 are demonstrated on a 10 μm-drift layer with a doping concentration of 1.5 × 1016 cm−3. β-Ga2O3 JBS diodes with low Von = 0.64 V and a power figure of merit of 1.03 GW/cm2 show great potential for future high-voltage and high-efficiency power electronics.

High-performance ceramic coatings for additive manufacturing biofunctional titanium alloy by regulating precipitation orientation

To prepare high-performance plasma electrolytic oxidation (PEO) coatings with excellent wear resistance and antibacterial activity on biofunctional alloys, Ti-Cu alloy was fabricated by additive manufacturing (AM) technique with controlled crystalline orientation of precipitates to enhance Cu ions release during PEO. In contrast to ingot metallurgical (IM) Ti-Cu alloy with Ti2Cu-(103)-oriented, the Ti2Cu-(110)-oriented in AM-Ti-Cu alloy exhibits a lower work function and inferior corrosion resistance due to its low atomic close-packing. This facilitates the release of Cu ions by promoting valence electron escape from the 4 s energy level during PEO to promote forming a higher content copper oxide (CuO). Subsequent to the PEO treatment, the AM-PEO coating contains more CuO (44.44 wt%) compared to the IM-PEO coating (3.6 wt%), resulting in better corrosion resistance and a lower friction coefficient (0.13 for AM-PEO and 0.34 for IM-PEO). The antibacterial efficacy of AM-PEO coating reached 99.62 %. This study highlights the advantage of regulating precipitate phase orientation in AM processes as an innovative approach to efficiently fabricate functional PEO coatings for alloys.

An energy-band modulated p-GaN/InGaN/AlN p-channel MESFET with high ION/IOFF ratio and steep subthreshold swing

In this work, we report on the high-performance p-GaN/InGaN/AlN multi-heterostructure p-channel metal–semiconductor field effect transistors (MESFETs) with energy-band modulated quantum well-like InGaN channel and low work function metal tungsten (W) as the gate material. A negative threshold voltage (VTH) of −0.35 V is achieved by precisely controlling the self-aligned etching depth at the active region. Benefiting from the enhanced hole confinement, the ION/IOFF ratio and subthreshold swing of the fabricated-channel MESFET are extracted to be 1.2 × 107 and 66 mV/dec, respectively, at room temperature. The idealized Schottky interface with TMAH and post-gate-annealing treatment shows an ultra-low voltage hysteresis of 0.08 V extracted at subthreshold area in the dual-sweep transfer curves.

Investigating the dilute magnetic semiconductor behavior of 4d transition metal adsorption on B4C3

We conducted a systematic investigation of B4C3 adsorbed with 4d-transition metals (4d-TMs), including Tc, Cd, Mo, Nb, Rh, Ru, and Ag, using first principles. This study involved an evaluation of structural, electronic, and magnetic properties. When single atom adsorption was adsorbed to B4C3 using elements such as Tc, Nb, Rh, Ru, and Ag, it demonstrated characteristics of a diluted magnetic semiconductor (DMS), manifesting magnetic moments. Conversely, Cd, Mo, and Pd exhibited behavior consistent with non-magnetic semiconductors. Ferromagnetic (FM) and antiferromagnetic (AFM) arrangements were formed through the adsorption of 2TM atoms on B4C3. In the FM setup, Ru and Nb uphold their roles as DMS. Interestingly, Tc and Rh exhibit half-metal behavior in this configuration, displaying their potential utility in spintronics applications. In the AFM configuration, Tc displayed half-metallic behavior, while the other metals maintained the same characteristics observed in the case of single TM adsorption. The reactivity of Nb-B4C3 is notably high owing to its low work function, whereas Cd-B4C3 is observed to be less reactive. AFM coupling is favorable in the 2Nb-, 2Rh-, and 2Ru-B4C3 systems, while 2Tc-B4C3 displays FM coupling. Transition metals belonging to the 4d series hold the potential to enhance the properties of B4C3, including its half-metallic, metallic, and semiconductor characteristics. These findings suggest the potential use of 4D transition metals adsorbed on B4C3 as a prospective material for spintronics and magnetic storage applications in the future.

Optimizing the d-band center of Pd/CoPcS-Ti3C2Tx to enhance SOD/CAT-mimicking activities in the treatment of osteoarthritis

The development and pathogenesis of osteoarthritis (OA) are closely related to the redox imbalance caused by the overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the inflammatory microenvironment. Herein, we developed Pd/CoPcS-Ti3C2Tx nanozymes combining cobalt sulfonated phthalocyanine (CoPcS) and titanium carbide (Ti3C2Tx) nanosheets by noncovalent π-π conjugation for loading of ultrafine Pd nanoclusters, as the superoxide dismutase (SOD) and catalase (CAT) mimics for OA therapy. The electron donor CoPcS-Ti3C2Tx facilitated electron transfer to Pd, effectively modulating the d-band center of Pd close to the Fermi energy level, which enhanced the adsorption energy of free radicals and decreased reaction energy barriers. As expected, Pd/CoPcS-Ti3C2Tx nanozymes had a lower electron escape work function than Ti3C2Tx, with improved photothermal conversion efficiency (49.1%) and enzyme catalytic activity. Experiments in vitro demonstrated that the SOD/CAT-mimicking Pd/CoPcS-Ti3C2Tx antioxidant system effectively eliminated ROS and RNS, inhibited inflammatory factors, restored mitochondrial function, and prevented energy deficiency, leading to a reduction in chondrocyte apoptosis. Particularly, near-infrared (NIR) radiation further enhanced the effects. In vivo studies proved the potent preventative effect of Pd/CoPcS-Ti3C2Tx on OA progression as well as its biosafety. This study is expected to provide a promising strategy for designing highly active nanozymes for the treatment of inflammatory diseases.

A simply prepared amine oxide molecule as a low work function cathode modifier in organic photovoltaics for harvesting ambient light

Organic photovoltaics (OPV) that possibly convert ambient lights to electric energy are under the spotlight as a power supplier for portable, wearable, and Internet of Things devices. In order to enable the commercialization of ambient light harvesters, it is imperative to design and synthesize device components that offer cost-effectiveness, uniform deposition, and efficient charge extraction/collection. Here, we introduce a simple cathode interlayer (CIL) named EtNO for OPV-based ambient light harvesters. EtNO is designed with a chemical structure that does not require complicated conjugated units and is synthesized through a one-step procedure. EtNO CIL shows efficient reductions in the work function of electrodes, attributed to an interfacial dipole induced from an interaction between amine oxide group of EtNO and electrodes. Furthermore, EtNO forms a uniform layer through solution-processing without deteriorative effects on the surface of photoactive layer in OPVs. Therefore, the OPV with EtNO CIL exhibits an improved performance with an output power density of 79.2 μW cm–2 under light emitting diode illumination (1000 lx, 254 μW cm–2) compared to the device with conventional PDINO CIL (73.1 μW cm–2). Studies conducted on OPVs under halogen light illumination and on large-area devices further demonstrate the significant potential of EtNO as a CIL.

A Study on the Field Emission Characteristics of High-Quality Wrinkled Multilayer Graphene Cathodes.

Field emission (FE) necessitates cathode materials with low work function and high thermal and electrical conductivity and stability. To meet these requirements, we developed FE cathodes based on high-quality wrinkled multilayer graphene (MLG) prepared using the bubble-assisted chemical vapor deposition (B-CVD) method and investigated their emission characteristics. The result showed that MLG cathodes prepared using the spin-coating method exhibited a high field emission current density (~7.9 mA/cm2), indicating the excellent intrinsic emission performance of the MLG. However, the weak adhesion between the MLG and the substrate led to the poor stability of the cathode. Screen printing was employed to prepare the cathode to improve stability, and the influence of a silver buffer layer was explored on the cathode's performance. The results demonstrated that these cathodes exhibited better emission stability, and the silver buffer layer further enhanced the comprehensive field emission performance. The optimized cathode possesses low turn-on field strength (~1.5 V/μm), low threshold field strength (~2.65 V/μm), high current density (~10.5 mA/cm2), and good emission uniformity. Moreover, the cathode also exhibits excellent emission stability, with a current fluctuation of only 6.28% during a 4-h test at 1530 V.

Strong electron correlation-induced Mott-insulating electrides of Ae5X3 (Ae = Ca, Sr, and Ba; X = As and Sb)

The presence of interstitial electrons in electrides endows them with interesting attributes, such as low work function, high carrier concentration, and unique magnetic properties. Thorough knowledge and understanding of electrides are thus of both scientific and technological significance. Here, we employ first-principles calculations to investigate Mott-insulating Ae5X3 (Ae = Ca, Sr, and Ba; X = As and Sb) electrides with Mn5Si3-type structure, in which half-filled interstitial electrons serve as ions and are spin-polarized. The Mott-insulating property is induced by strong electron correlation between the nearest interstitial electrons, resulting in spin splitting and a separation between occupied and unoccupied states. The half-filled antiferromagnetic configuration and localization of the interstitial electrons are critical for the Mott-insulating properties of these materials. Compared with that in intermetallic electrides, the orbital hybridization between the half-filled interstitial electrons and the surrounding atoms is weak, leading to highly localized magnetic centers and pronounced correlation effects. Therefore, the Mott-insulating electrides Ae5X3 have very large indirect bandgaps (∼0.30 eV). In addition, high pressure is found to strengthen the strong correlation effects and enlarge the bandgap. The present results provide a deeper understanding of the formation mechanism of Mott-insulating electrides and provide guidance for the search for new strongly correlated electrides.

Insight into the crystal facet-dependent Cr(VI) reduction: A comparative study of pyrite {100} and {111} facets

The migration and transformation of hexavalent chromium (Cr(VI)) in the environment are regulated by pyrite (FeS2). However, variations in pyrite crystal facets influence the adsorption behavior and electron transfer between pyrite and Cr(VI), thereby impacting the Cr(VI) reduction performance. Herein, two naturally common facets of pyrite were synthesized hydrothermally to investigate the facet-dependent mechanisms of Cr(VI) reduction. The experimental results revealed that the {111} facet exhibited approximately 1.30–1.50 times higher efficiency in Cr(VI) reduction compared to the {100} facet. Surface analyses and electrochemical results indicated that {111} facet displayed a higher iron-sulfur oxidation level, which was affected by its superior electrochemical properties during the reaction with Cr(VI). Density functional theory (DFT) calculations demonstrated that the narrower band gap and lower work function on {111} facet were more favorable for the electron transfer between Fe(II) and Cr(VI). Furthermore, different adsorption configurations were observed on {100} and {111} surfaces due to the unique arrangements of Fe and S atoms. Specifically, O atoms in Cr2O72− directly bound with the S sites on {100} but the Fe sites on {111}. According to the density of states (DOS), the Fe site had better reactivity than the S site in the reaction, which appeared to be related to the fracture of S-S bonds. Additionally, the adsorption configuration of Cr2O72− on {111} surface showed a stronger adsorption energy and a more stable coordination mode, favoring subsequent Cr(VI) reduction process. These findings provide an in-depth analysis of facet-dependent mechanisms underlying Cr(VI) reduction behavior, offering new insights into studying environmental interactions between heavy metals and natural minerals.

The addition of fluorine atoms and alkyl chains to aromatic ligand dipole for enhancing stability and photoelectronic properties of formamidinium perovskite surfaces

The long-term stability on perovskite surfaces limits the practical application of perovskite solar cells (PSCs). Adding multifunction ligand can deal with this issue, however, the structure diversity of ligand and perovskite surface leads to the complicated adsorptive interaction, affecting the improvement effect of the stability and photoelectric properties. In this work, strongly electronegative fluorine atoms and alkyl chain with different length are introduced into aromatic ligand dipole to modify the polarity, regulating the phase stability, energy state and photoelectric properties of formamidinium perovskite (FAPbI3) surfaces. The results show the adsorption and interaction energy of positive ligand dipoles on the I-terminated surface decrease with the increase of polarity, which displays stronger ordered π-π stack and adsorption anchoring of ligand dipoles and thus decreasing the formation energy to improve the phase stability. The positive 4-Trifluoromethyl-phenethylammonium (CF3-PEA) with the highest polarity obtains the highest stability and shifts work function (WF) upward from 6.21 eV to the highest 6.46 eV. The negative CF3-PEA adsorbs on the PbI2-terminated surface induced by CF3•••Pb and π•••I interaction, achieving the stable phase with lower formation energy and lowest WF 5.61 eV. This work provides tutorial for optimizing performance of PSCs by the addition of ligand dipoles.

Mo‐Doped BiVO4 as a Fast Electrode Reaction Kinetics Catalyst in Na−O2 Batteries

AbstractThe highly insulated solid discharge products in sodium‐oxygen (Na−O2) batteries induce large polarization and thus heavily threaten their cycle life. Controlment of discharge products taking efficient catalyst is a best way to solve this problem. Here, Mo‐doped BiVO4 as the catalyst produces large amounts of carrier, thus boosting the battery reaction and reducing the overpotential under the light assistance. Compared with the BiVO4 without Mo doping, the doped one has a lower recombination of photogenerated carriers, thus benefiting a large polarization suppression and Na−O2 batteries running for over 270 cycles under 3.65 V as well as a fine rate performance. Besides, Mo doping reduces the size of BiVO4, beneficial for the carrier transportation and more reactions due to the large specific surface area. Experiment combined with theoretical calculation shows that Mo doping is advantageous to enhancing catalytic activity of BiVO4 due to a lower work function for easier electron extraction, thus enhancing Na2O2 decomposition capability. This work undoubtedly inspires photocatalysts′ use for solving the insulated solid discharge products decomposition in metal‐O2 batteries and provides a guide for other photocatalysts possibilities.

Surface Work Function Modifier to Modulate Electrolyte Decomposition on Negative Electrode in Lithium‐Ion Batteries

AbstractThe persistent decomposition of electrolytes on graphite and silicon electrodes in lithium‐ion batteries (LIBs) is typically mitigated by the formation of a solid electrolyte interphase (SEI). However, the inadequate formation and chemo‐mechanical degradation of SEI leads to re‐exposure of electrode to electrolyte, contributing to the deterioration of LIBs. To address this issue, tris(2,4‐pentanedionato)indium(III) (InAc) is incorporated into the work function tailoring additive. While conventional additives strengthen the chemo‐mechanical properties of SEI through compositional modifications derived from specific elements, InAc uniquely alters charge transfer across the electrode surface, facilitated by high or low work function layer. This additive establishes an interlayer between the SEI and graphite/SiO surfaces, attributed to its tailored lowest unoccupied molecular orbital energy level. Consequently, the exposure of graphite surface to the electrolyte is minimized by interlayer during cycling. The interlayer possesses a higher work function than lithiated graphite and suppresses further electrolyte decomposition on graphite. In contrast, the interlayer on SiO decreases work function of SiO surface, which promotes the formation of inorganic SEI on SiO. Hence the degradation of SEI is suppressed with LiIn layer at SiO electrode. This leads to a reduction in the ongoing accumulation of SEI, thereby enhancing durability of LIBs.

Uniaxial-Oriented Perovskite Films with Controllable Orientation.

Perovskite films with large crystal size, preferred orientation, and facile fabrication process, combining advantages of single-crystal and polycrystalline films, have gained considerable attention recently. However, there is little research on the facet properties of perovskite films. Here, (111)- and (001)-oriented perovskite films with bandgaps ranging from 1.53 to 1.77eV, and systematically investigated their orientation-dependent properties are achieved. The (111)-oriented films show electron-dominated traps and the (001)-oriented films show hole-dominated traps, which are related to their atomic arrangement at the surface. Compared with the (001)-oriented films, the (111)-oriented films exhibit lower work function and superior water/oxygen robustness. For the wide-bandgap films, the lattice of the (001)-oriented film provides an unobstructed passage for ion migration. Comparably, the (111)-oriented films exhibit suppressed ion migration and excellent phase stability. The optimized unencapsulated solar cells based on both (001) and (111) orientations show a similar high efficiency of ≈23%. The (111)-oriented solar cell exhibits excellent stability, maintaining 95% of its initial efficiency after 1500h maximum power point (MPP) tracking test, and 97% initial efficiency after 3000h aging in ambient conditions. This work paves the way for the rational design, controllable synthesis, and targeted optimization of uniaxial-oriented perovskite films for various electronic applications.

Study on schottky barrier of Cu/Graphene/4H-SiC interface based on first principles

High stability 4H-SiC ohmic contact is currently a key technical challenge that silicon carbide devices urgently need to overcome. In the paper, the interfacial structures, atomic interactions and Schottky barrier height (SBH) of Cu/Graphene/4H-SiC were studied using the first-principles method. According to research, the SBH for Cu/G/4H-SiC is lower than the SBH for Cu/4H-SiC. The reasons for this phenomenon mainly include the following: 1. The graphene C atoms saturate the dangling bonds on the 4H-SiC surface and the influence of the metal-induced-gap-states (MIGS) at the interface is decreased. 2. A new phase is formed by inserting graphene between the Cu and 4H-SiC have low work functions. 3. An interfacial-electric-dipole layer (IEDL) formed at the interface of 4H-SiC and graphene may also reduce the SBH. These results make them to be promising candidates for future radiation resistant electronics.

First Principle Study on Schottky Barrier at Ni/Graphene/4H-SiC Interface

High stability 4H-SiC ohmic contact is currently a key technical challenge that silicon carbide devices urgently need to overcome. It is important to reduce the Schottky barrier height (SBH) at the Ni/4H-SiC interface to optimize ohmic contact. In this paper, the mechanisms of graphene layer changing Ni/4H-SiC interface Schottky barrier height (SBH) are studied based on the first-principles method within the local density approximation. Theoretical studies have shown that graphene intercalation can reduce the SBH of Ni and 4H-SiC interfaces. The reason of SBH reduction may be that the graphene C atoms saturate the dangling bonds on the 4H-SiC surface and the influence of the metal-induced energy gap state at the interface is reduced. In addition, the new phase formed at the interface of graphene and silicon carbide has a lower work function. Furthermore, an interfacial electric dipole layer may be formed at the 4H-SiC/graphene interface which may also reduce the SBH. These results make them to be promising candidates for future radiation resistant electronics.

Visible-light‑sensitive AgCu nanocomposites for sustainable inactivation of virus

The coronavirus disease 2019 (COVID-19) caused a large number of deaths and serious economic losses. Safety precautions and effective measures are urgently demanded to control the virus spread in public places. Owing to the longevity of the viruses in the aerosols and surfaces, sustained nanomaterials with efficient antiviral abilities during both daytime and night appear to be a promising way to control virus spread. Here, AgCu nanocomposites, which are outstanding antibacterial and antiviral elements, including Ag2Cu2O3 and AgCuO2, have been successfully prepared via a simple co-precipitation method for inactivation of model Qbeta (Qβ) bacteriophage. Notably, Ag2Cu2O3 has uniform nanorods morphology with a width of 50–100 nm and a length of 200–500 nm, regular elemental states of Cu2+ and Ag+, and good visible light response. Instead, AgCuO2 has more complex elemental states of Cu2+, Ag+, and Ag3+, including morphology with large particles of 500–1000 nm surrounded by small nanorods and nanoplates. Density functional theory (DFT) calculations showed that Ag2Cu2O3 has a lower work function than AgCuO2, indicating the charges can be better released from the surface. The accumulated surface charge can bind to the virus to inactivate it. As a result, Ag2Cu2O3 shows outstanding antiviral properties with a 6-log reduction (99.9999 %) of Qβ phage after 45 min contact under dark condition, and the activity can be further promoted to 7.5-log inactivation of Qβ phage after the same time contact under visible light irradiation, revealing its potential to sustainably prevent viruses spread in indoor environments.

Investigation of work function and quantum capacitance of OH-terminated MXenes as supercapacitor electrodes: A theoretical perspective

MXene has shown promise in supercapacitor electrodes for energy storage devices. As key parameters to develop new electronic devices, the quantum capacitance and work function (WF) of OH-terminated MXenes with 3d, 4d, d transitional metals are investigated by density functional theory. The most stable configurations of 13 M2C(OH)2 MXenes are found, which are further confirmed by negative formation energies. The low WFs of M2C(OH)2 make them become potential candidates as thermionic electron emitters, especially for Sc2C(OH)2 and Lu2C(OH)2 with extra low WFs. Sc2C(OH)2, Cr2C(OH)2, Y2C(OH)2, and Lu2C(OH)2 are considered as negative electrodes, Other nine systems are potential positive electrodes for larger |Qp|/|Qn| than 1, especially for V2C(OH)2, Nb2C(OH)2, and Mo2C(OH)2. Th wide voltage maintains the electrode types of all systems unchanged, but drastically increases the |Qp|/|Qn| of V2C(OH)2. The quantum capacitance of M2CT2 with different terminations is further explored.

Constructing diatomic catalyst on MoSSe achieves ultra-low overpotential for nitrogen fixation: First-principles study

The collaborative interaction between the diatoms can enhance the catalytic activity of the transition metal atoms and facilitate the activation of nitrogen molecules. Based on first-principles calculations, the feasibility of electrocatalytic nitrogen fixation as a diatomic catalyst (TMs@MoSSe) formed by transition metal dimers (V, Cr, Mn, Fe, Co, and Ni) dispersed on a two-dimensional Janus MoSSe monolayer is systematically investigated. The results demonstrate that the MoSSe monolayer loaded with double chromium atoms (Cr2@MoSSe) exhibits exceptional catalytic activity, showcasing an extremely low overpotential of 0.17 V in the enzymatic mechanism. Specifically, this research elucidates the nitrogen reduction capacity of the electrocatalyst by considering its magnetic moment and work function, concluding that a lower work function corresponds to enhanced catalytic activity. Additionally, the product of the magnetic moment and valence electron numbers of the transition metal atoms (μTM⋅dTM) exhibits an inverted volcano relationship with the overpotential. These findings can provide valuable insights for the design of diatomic catalysts.