Carrier Transport Mechanism Research Articles

Substrate binding and inhibition of the anion exchanger 1 transporter.

Anion exchanger 1 (AE1), a member of the solute carrier (SLC) family, is the primary bicarbonate transporter in erythrocytes, regulating pH levels and CO2 transport between lungs and tissues. Previous studies characterized its role in erythrocyte structure and provided insight into transport regulation. However, key questions remain regarding substrate binding and transport, mechanisms of drug inhibition and modulation by membrane components. Here we present seven cryo-EM structures in apo, bicarbonate-bound and inhibitor-bound states. These, combined with uptake and computational studies, reveal important molecular features of substrate recognition and transport, and illuminate sterol binding sites, to elucidate distinct inhibitory mechanisms of research chemicals and prescription drugs. We further probe the substrate binding site via structure-based ligand screening, identifying an AE1 inhibitor. Together, our findings provide insight into mechanisms of solute carrier transport and inhibition.

Carrier transport mechanism of Mg/Pt/Au Ohmic contact on p-GaN/AlGaN/GaN platform with ultra-low resistivity

In this work, the carrier transport mechanism of Mg/Pt/Au Ohmic contact on p-GaN/AlGaN/GaN with a very low specific contact resistivity of 1.98 × 10−5 Ω cm2 is investigated. Secondary ion mass spectroscopy measurement results show that the Mg concentration near the p-GaN surface increases form 8 × 1019 to 7 × 1020/cm3 for Mg/Pt/Au contact after annealing. It indicates that Mg atoms from the Mg/Pt/Au metal stack diffuse into the p-GaN during annealing, forming a heavily Mg doped p++-GaN layer with a depth of about 3 nm. The sheet resistance Rsh depends on temperature for Mg/Pt/Au contacts on p-GaN/GaN, indicating that the influence of 2DHG on carrier transport mechanisms at the metal/p-GaN interface was eliminated. For Mg/Pt/Au contacts at ≥360 K, specific contact resistivity reasonably follows T−1, which indicates that the band conduction of Schottky theory dominates the carrier transport. For Mg/Pt/Au contacts at 200–360 K, the electrical resistivity reasonably follows T−1/4, indicating variable-range hopping (VRH) conduction through Mg-related deep-level defects (DLD). Based on the VRH conduction model, the effective barrier height (qφ) of the Mg-related DLD band is extracted as 0.265 eV, which well matches the excellent Ohmic contact.

Optimization of Activation Annealing Condition for Boron‐Implanted Diamond

Impurity activation of dopants implanted in diamond is one of the crucial issues for device application of diamond. Boron impurity atoms are introduced in diamond, which expectedly act as acceptors, by ion implantation technique, and are investigated the optimum annealing time for the effective dopant activation. The impurity doping is performed by boron ion implantation at multiple incident energies to obtain a uniform dopant concentration from the surface to 350 nm depth followed by activation annealing at 1300 °C for 5–240 min. The electrical properties of specific resistance, carrier concentration, and conduction type are analyzed as a function of temperature from room temperature to 873 K. The estimated ionization energy is strongly dependent on the annealing time and asymptotically approaches to 0.3 eV, which is theoretically expected ionization energy of acceptor boron, with increasing annealing time. A shorter annealing time ( does not sufficiently recover radiation damages caused by ion implantation forming deep levels, which act as irregular conduction. It is consequently found that an optimum window of annealing time for effective dopant activation and suggested carrier transport mechanisms depending on the annealing time.

Study on the law and mechanism of anisotropic conductivity of carbon nanotubes film prepared by floating catalytic chemical vapor deposition method

Carbon nanotubes (CNTs) film has attracted extensive attention in the field of electronics, sensors, and other potential applications due to their excellent electrical conductivity. The conductivity of CNTs film is one of the most important aspects of engineering applications. This study investigates the conductivity of CNTs film with varying areal density, prepared using the floating catalyst chemical vapor deposition (FCCVD) method and densified by rolling. The square resistance of pre- and post-rolling films was measured to characterize the electrical properties. Experimental results indicate that square resistance decreases with increasing areal density and stabilizes eventually. A mathematical formula was derived to explain the relationship between areal density and square resistance, incorporating volume and areal density formulas. Experimental data curves of pre- and post-rolling films were fitted, yielding mathematical relations consistent with the derived formulas. The electrical conductivity of post-rolling CNTs film was superior to pre-rolling in experiment and calculation. The charge carrier transport mechanism in CNTs film was studied by analyzing its internal structure and electrical properties. Surface conductivity was over 1000 times higher than volume conductivity, attributed to the distribution of CNTs bundles in collection and thickness directions. Charge carrier transport capacity decreased with increasing layers in thickness direction due to contact resistance and large resistance at tube–tube junctions. Layers of CNTs near the current application surface significantly contribute to charge carrier transport at high areal density levels.

A critical experimental evaluation of hexagonal boron nitride, graphene oxide and graphite as thermally conductive fillers in organic PCMs

Composite phase change materials (CPCMs), consisting of nanofillers embedded inside conventional PCMs such as salt hydrates or paraffins, are emerging candidates for large-scale latent heat storage systems or electrochemical applications. High thermal conductivity and thermal diffusivity of CPCMs are crucial prerequisites for practical utilization, in addition to good intrinsic enthalpy of fusion and volumetric heat capacity of the pristine PCMs. This paper presents an exclusive evaluation of graphite, hexagonal boron nitride (HBN), and graphene oxide nanoparticles as thermally conducting nanofillers across different loading ranges inside the paraffin matrix. The thermal performance of these CPCMs is compared by investigating multiple thermal properties, such as the melting temperature, degradation rate, and dispersion efficiency. Despite the similar intrinsic thermal properties of graphite, HBN and graphene oxide, their incorporation enhances the thermal performance of pure paraffin to different extents, by 137.6 %, 192.2 % and 344.1 % in thermal conductivity as well as by 189.0 %, 204.1 % and 202.1 % in thermal diffusivity, respectively, which is attributed to the conductive channels established by these nanofillers and the much-reduced thermal contact resistance across the interphase. Although these three types of particles possess analogously hexagonal structures, it was found that they interacted differently with the paraffin matrix at low (1 wt%) and high (15 wt%) filler loadings. The latent heat capacity of paraffin/GO was 3.8 % higher than that of paraffin/HBN and paraffin/graphite. Overall, this study provides a novel understanding of the transport mechanisms of heat carriers inside CPCMs, so the thermal performance for wider applications can be predicted, which will be invaluable for catering future sustainable energy needs.

Ab Initio Time-Domain Study of Charge Relaxation and Recombination in N-Doped Cu2O.

Cu2O is a good photoelectric material with excellent performance, and its crystal structure, electronic structure, and optical properties have been extensively studied. To further illustrate the charge distribution and the carrier transport in this system, the e-h recombination dynamics was studied. It is found that N doping induced a shallower impurity band above the VBM, leading to significant charge localization around the impurity atom. NAMD simulation reveals that the N doping system possesses a longer e-h nonradiative recombination time scale. Therefore, we demonstrate that the formation of the impurity band and charge localization play an essential role in suppressing e-h recombination in N doping systems. This work is conducive for understanding the carrier transport mechanism in N-doped Cu2O.

Role of defects on carrier dynamics and transport mechanism in Bi2Te3 single crystals

Defects play an important role in determining the type of carriers as well as in tunning the physical properties of layered materials. In this study, we have demonstrated that by varying the growth kinetics one can control the defects and can achieve electrons or holes dominated Bi2Te3 single crystals using the modified Bridgman method. The correlation between structural defects and the type of dominant charge carriers in crystals is discussed using X-ray diffraction and Hall resistivity. Electrons are found to be originating from Te vacancy type defects, while holes are manifested from predominant structural defects viz. BiTe antisite defects or interstitial Te atoms. We observe that the alteration of charge carriers from electrons to holes has enhanced magnetoresistance from 103% to 224%. The enhancement in magnetoresistance emerges from the 2D multichannel quantum coherent conduction mechanism.

Surface Rh-Boosted Photoelectrochemical Water Oxidation of α-Fe2O3 by Reduced Overpotential in the Rate-Determining Step.

The photoelectrochemical behavior of Rh cluster-deposited hematite (α-Fe2O3) photoanodes (α-Fe2O3@Rh) was investigated. The interactions between Rh clusters and α-Fe2O3 nanorods were elucidated both experimentally and computationally. A facile UV-assisted solution casting deposition method allowed the deposition of 2 nm Rh clusters on α-Fe2O3. The deposited Rh clusters effectively enhanced the photoelectrochemical performance of the α-Fe2O3 photoanode, and electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis were applied to understand the working mechanism for the α-Fe2O3@Rh photoanodes. The results revealed a distinctive carrier transport mechanism for α-Fe2O3@Rh and increased carrier density, while the absorbance spectra remained unchanged. Furthermore, density functional theory (DFT) calculations of the oxygen evolution reaction (OER) mechanism corresponded well with the experimental results, indicating a reduced overpotential of the rate-determining step. In addition, DFT calculation models based on the X-ray diffraction (XRD) measurements and X-ray photoelectron spectroscopy (XPS) results provided precise water-splitting mechanisms for the fabricated α-Fe2O3 and α-Fe2O3@Rh nanorods. Owing to enhanced carrier generation and hole transfer, the optimum α-Fe2O3@Rh3 sample showed 78% increased photocurrent density, reaching 1.12 mA/cm-2 at 1.23 VRHE compared to that of the pristine α-Fe2O3 nanorods electrode.

Optimization of Intercalated 2D BiOCl Sheets into Bi2WO6 Flowers for Photocatalytic NH3 Production and Antibiotic Pollutant Degradation.

Photocatalytic N2 fixation is a complex reaction, thereby prompting researchers to design and analyze highly efficient materials. Herein, one-pot hydrothermal Bi2WO6-BiOCl (BW-BiOCl) heterojunctions were synthesized by varying the molar ratio of tungsten: chlorine precursor. Major morphological transformations in BiOCl were observed wherein it turned from thick sheets ∼230 nm in pure BiOCl to ∼30 nm in BW-BiOCl. This was accompanied by extensive growth of {001} facets verified from X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) analyses. A p-n heterojunction was formed between Bi2WO6 and BiOCl evidenced via photoluminescence (PL), time-resolved photoluminescence (TRPL), photocurrent response, and electrochemical impedance spectroscopy (EIS) analyses. The formation of heterojunction between Bi2WO6 and BiOCl led to the reduction of the work function in the BW-BiOCl 0.25 hybrid confirmed via ultraviolet photoelectron spectroscopy (UPS) analysis. BW-BiOCl 0.25 could produce ammonia up to 345.1 μmol·L-1·h-1 owing to the formation of a robust heterojunction with an S-scheme carrier transport mechanism. Recycle tests resulted in no loss in N2 reduction activities with post-catalytic analysis, showcasing the high stability of the synthesized heterojunction. Novel performance was owed to its excellent chemisorption of N2 gas on the heterojunction surface verified by N2-temperature programmed desorption (TPD). BW-BiOCl 0.25 also displayed a superior rate constant of 3.03 × 10-2 min-1 for 90 min CIP degradation time, higher than pristine BiOCl and Bi2WO6. Post-photocatalytic Fourier transform infrared (FTIR) spectroscopy of BW-BiOCl 0.25 revealed the presence of C-H stretching peaks in the range of 2850-2960 cm-1 due to adsorbed CIP and methanol species in CIP degradation and N2 fixation, respectively. This also confirmed the enhanced adsorption of reacting species onto the heterojunction surface.

Schottky barrier heights and electronic transport in Ga2O3 Schottky diodes

The Schottky contact, formed at the interface between a metal and a semiconductor, is instrumental in defining the electrical properties of Schottky barrier diodes (SBDs). The characteristics of the Schottky contact are contingent on the properties of interacting metal and semiconductor properties. Herein, we studied the carrier-transport mechanisms and electrical characteristics at room and elevated temperatures. These SBDs employ pre-treated Ga2O3 thin films and either Ni or Au Schottky contacts. The SBDs pre-treated (pre-T) via annealing at 900 °C under an N2 atmosphere for the Ni contact showed highest on/off ratio at room temperature. They also demonstrated ideality factors and Schottky barrier heights (SBHs) that remained relatively stable between 298 K and 523 K. To ascertain the SBH, ideality factors (n) derived from the thermionic emission (TE) and thermionic field emission (TFE) models were used, and results were subsequently compared. Moreover, SBDs employing Ni as the anode material exhibited lower SBHs than those employing Au. The pre-T Ni SBD was best described by the TFE model, wherein the SBH and ideality factor varied by 0.14 eV and 0.13, respectively, between 298 K and 523 K. Conversely, for pre-T Au, untreated Ni, and untreated Au SBDs, neither TE and TFE provided a satisfactory fit due to the ideality factor is greater than 2 at room temperature and the variation of SBH and n with temperature. These suggests that the transport mechanism should be described by other physical mechanisms. Without pre-treatment, both the Ni and Au SBDs exhibited more significant variation in the SBH and n with temperature. SBHs values were determined using measurement of current, capacitance and x-ray photoelectron spectroscopy, and were found to depend on the interface quality, indicating inhomogeneous SBH. Our results suggest that the use of annealing pre-treatments and anode metals with low work functions holds considerable potential for reducing Schottky barrier heights in Schottky diodes, thereby enhancing their electrical performance.

Effect of nano CdO-ZnO content on structural, thermal, optical, mechanical and electrical properties of epoxy composites

Cadmium oxide doped zinc oxide nanoparticles were synthesized by solution combustion technique. CdO-ZnO nanoparticles were reinforced into epoxy by ultrasonication technique. CdO-ZnO nano-particles are well known semiconducting materials which are found to exhibit excellent semiconducting behavior even at high frequencies. Hence it was introduced into epoxy to study the semiconducting nature of CdO-ZnO/epoxy composites. The polymer composites exhibited interesting phenomenon such as minimum heat losses at high frequencies indicating semi-conducting behaviour of the composites. The polymer composite was also analysed for its structural, thermal, optical and mechanical properties. The enhanced interaction of CdO-ZnO nanoparticles with epoxy has resulted in superior UV-shielding effeciency and mechanical properties. This paper mainly focusses upon the synthesis and development of CdO-ZnO/epoxy composites, the design and optimization of CdO-ZnO compositions, the mechanical toughening and failure mechanism, transport mechanism of charge carriers, conductivity relaxation, ionic polarization and prospects of CdO-ZnO/epoxy composites in various fields.

Threshold voltage shift model for p-GaN gate enhancement mode HEMT

In this paper, we based on the gate structure of p-GaN HEMT connected with Schottky diode and PIN diode and analyzed the threshold voltage shift mechanism under the influence of gate voltage. Based on the carrier transport mechanism, the electron injection current and hole injection current of the p-GaN layer is discussed and calculated, while the gate current model and threshold voltage shift model of the p-GaN HEMT are analyzed. The accuracy of the model is verified by comparing with the experimental data. The effects of p-GaN doping concentration, AlGaN barrier layer thickness and Al component on the gate current and VTH shift are discussed based on the model. By optimizing the device structure and process parameters, the gate current of HEMT can be reduced and the stability of VTH can be improved.

Investigations of Carrier Transport Mechanisms in Perovskite Solar Cells with Different Types of ZnO Layer

The interfacial mechanisms of carrier transport in perovskite solar cells with different types of zinc oxide (hydrothermal solution method (ZnOHT) and sol–gel method (ZnOSG)) are investigated. Power conversion efficiencies of the devices with ZnOHT and ZnOSG layers are 18.66% and 13.39%, respectively, which are significantly varied by the rates of photoelectron injection and electron–hole recombination. The space‐charge‐limited current and electrochemical impedance measurements both show that the device utilizing ZnOHT layer exhibits fewer internal defects compared to that with ZnOSG layer. Via transient absorption spectroscopy, faster injection of photoelectrons from the active layer to the transport layer occurs at ≈3.8 ps in the devices with ZnOHT layer, which is half of the value observed in devices with ZnOSG layer and benefits the device performance. Moreover, a faster electron–hole recombination in devices with ZnOSG degrades device performance due to the trap states in high‐defect‐density devices. Both device performances stably maintain a level higher than 98% of the initial value after over 600 h without encapsulation in glove box. Finally, the structural and electronic properties of charge transport layer can be controlled by the methods of preparation and ZnOHT shows great promise in enhancing perovskite solar cell efficiency with relatively low‐temperature process.

Effect of structure on semiconducting properties of a small molecule n-type organic semiconductor: Phenyl-C61-butyric acid methyl ester

The fullerene-based derivative phenyl-C61-butyric acid methyl ester (PCBM) has attracted attention as an n-type transistor channel and an organic photovoltaic material due to its solution processability, stability, and high electron mobility. However, disorder in solution-processed PCBM thin films makes understanding of charge carrier transport mechanisms difficult. We have fabricated PCBM-based field effect transistors and improved device performance by reducing electron trapping at the dielectric–semiconductor interface and improving charge carrier injection. Single-wall carbon nanotubes were successfully integrated into conventional gold electrodes to improve injection efficiency. Meyer–Neldel behavior has been investigated in a study of charge carrier transport in PCBM thin films. Crystallization of PCBM was observed during the measurement. We find that charge carriers hop between molecules in mostly amorphous regions from 145 to 240 K. The transport is facilitated by the formation of more crystallized regions when samples are heated as high as 240 K.

Unravelling the crossover amongst band and various hopping conduction mechanisms in Mo doped ZnO thin films owing to carrier localization at defects

Understanding the carrier transport mechanism of transparent conducting oxides is crucial for its application in optoelectronic devices. Although, electrical transport mechanisms of various trivalent cation doped ZnO films have been reported adequately, a substantial study is needed to understand the transport mechanism in ZnO doped with higher valence (>+3) dopants. Unlike Al, In and Ga doped ZnO where metal-insulator transition is commonly observed, in this study, the crossover amongst band and various hopping mechanisms has been observed in the temperature range of 300–10 K in Mo doped ZnO films deposited at various substrate temperatures. All the films show electrons as the majority charge carriers and notably, the film deposited at 573 K shows the highest conductivity value of 167.22 (Ω.cm)−1. In-depth analyses of the conduction mechanism reveal grain boundary scattering dominated band conduction at and not far below the room temperature, which is shifted towards nearest neighbor hopping (NNH), and then to Mott variable range hopping (VRH) type of conductions as the temperature is decreased further. Unfamiliarly, a modified Efros-Shklovskii (ES) VRH type of conduction mechanism is shown to prevail in the lowest measured temperature range (∼30–10 K). Unprecedentedly, it is demonstrated here that the activation energies for various conduction mechanisms are higher at lower vacuum condition (∼10−1 mbar) as compared to those measured at higher vacuum condition (∼10−3 mbar) implying an added role of the surface traps in the charge transport process. The temperature dependent conductivity and X-ray photoelectron spectroscopy (XPS) studies proclaim that the film deposited at 573 K possess fewer defects related disorder for carrier localization as compared to the films deposited at 523 K and 698 K.

Fermi level induced band edge alignment and band bending in Ag3PO4/Cu2O p-n heterojunction for proficient photocatalytic applications

Fabrication of binary p-n heterojunction and the band alignment at the interface of the individual semiconductor photocatalyst has been extensively studied to verify superior charge separation and migration capability in photocatalytic applications. Here, a simple wet chemical followed by a hydrothermal fabrication strategy was introduced for the development of the binary p-n Ag3PO4/Cu2O heterostructures. The tunable band structure of individual semiconductors with the work function (φ), witnessed a band bending at the space charge region. The bending at the interface induces a carrier concentration gradient and manifests a rectifying current transport diode. The fabricated p-n heterostructures and carrier migration between n-type Ag3PO4 and p-type Cu2O were verified by different morphological and physicochemical methods. The band banding at the interface, leading to a narrow depletion region, favors the tunneling of electron-hole pairs through a Z-scheme carrier transport mechanism. The electron-hole pair movement has further been confirmed by considering the band edge position after contact, photocatalytic scavengers, and the radical trapping experiment. The Ag3PO4/Cu2O p-n heterojunction photocatalyst manifested a 737.4 μmol g−1h−1 of H2 generation and 91% endosulfan degradation efficiency, these are 12 and 9 times higher than that of pure Ag3PO4. The p-n heterojunction photocatalyst displayed a higher current density with electron-hole migration efficiency, synergistically enhancing the catalytic activity through the interfacial space charge junction.

Metal Halide Perovskite Photo-Field-Effect Transistors with Chiral Selectivity.

Organic-inorganic (hybrid) metal halide perovskites (MHPs) incorporating chiral organic ligand molecules are naturally sensitive to left- and right-handed circular polarized light, potentially enabling selective circular polarized photodetection. Here, the photoresponses in chiral MHP polycrystalline thin films made of ((S)-(-)-α-methyl benzylamine)2PbI4 and ((R)-(+)-α-methyl benzylamine)2PbI4, denoted as (S-MBA)2 PbI4 and (R-MBA)2PbI4, respectively, are investigated by employing a thin-film field-effect transistor (FET) configuration. The left-hand-sensitive films made of (S-MBA)2PbI4 perovskite show higher photocurrent under left-handed circularly polarized (LCP) light than under right-handed circularly polarized (RCP) illumination under otherwise identical conditions. Conversely, the right-hand-sensitive films made of (R-MBA)2PbI4 are more sensitive to RCP than LCP illumination over a wide temperature range of 77-300 K. Furthermore, based on FET measurements, we found evidence of two different carrier transport mechanisms with two distinct activation energies in the 77-260 and 280-300 K temperature ranges, respectively. In the former temperature range, shallow traps are dominant in the perovskite film, which are filled by thermally activated carriers with increasing temperature; in the latter temperature range, deep traps with one order of magnitude larger activation energy dominate. Both types of chiral MHPs show intrinsic p-type carrier transport behavior regardless of the handedness (S or R) of these materials. The optimal carrier mobility for both handedness of material is around (2.7 ± 0.2) × 10-7 cm2 V-1 s-1 at 270-280 K, which is two magnitudes larger than those reported in nonchiral perovskite MAPbI3 polycrystalline thin films. These findings suggest that chiral MHPs can be an excellent candidate for selective circular polarized photodetection applications, without additional polarizing optical components, enabling simplified construction of detection systems.

Enhancing Carrier Transport via σ-Linkage Length Modulation in D-σ-A Semiconductors for Photocatalytic Oxidation.

Carrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ-linkage length modulation strategy to enhance carrier transport in imidazole-alkyl-perylene diimide (IMZ-alkyl-PDI, corresponding to D-σ-A) photocatalysts by controlling π-π stacking distance. Ethyl-linkage can shorten π-π stacking distance (3.19 Å) the most among IMZ-alkyl-PDIs (where alkyl=none, ethyl, and n-propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ-ethyl-PDI exhibits remarkable enhancement in phenol degradation with 32-fold higher rates than IMZ-PDI, as well as the oxygen evolution rate (271-fold increased). In microchannel reactors, IMZ-ethyl-PDI also presents 81.5 % phenol removal with high-flux surface hydraulic loading (44.73 L m-2 h-1 ). Our findings provide a promising molecular design guideline for high-performance photocatalysts and elucidate crucial internal carrier transport mechanisms.

Enhancing Carrier Transport via σ‐Linkage Length Modulation in D‐σ‐A Semiconductors for Photocatalytic Oxidation

AbstractCarrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ‐linkage length modulation strategy to enhance carrier transport in imidazole‐alkyl‐perylene diimide (IMZ‐alkyl‐PDI, corresponding to D‐σ‐A) photocatalysts by controlling π–π stacking distance. Ethyl‐linkage can shorten π–π stacking distance (3.19 Å) the most among IMZ‐alkyl‐PDIs (where alkyl=none, ethyl, and n‐propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ‐ethyl‐PDI exhibits remarkable enhancement in phenol degradation with 32‐fold higher rates than IMZ‐PDI, as well as the oxygen evolution rate (271‐fold increased). In microchannel reactors, IMZ‐ethyl‐PDI also presents 81.5 % phenol removal with high‐flux surface hydraulic loading (44.73 L m−2 h−1). Our findings provide a promising molecular design guideline for high‐performance photocatalysts and elucidate crucial internal carrier transport mechanisms.

Transport and recombination properties of doped SiC nanoribbons with different atoms substituted by group-V elements

Based on semiconductor theory and optimization data derived from first-principles, we simulate the conductive and recombination properties of group-V doped zigzag SiCNRs (ZSiCNRs), through in-depth analysis of different substitutional doping models, to unveiling the mechanism of carrier transport in nanodevices. It’s found that though there are two impurity energy levels whether C or Si is substituted in doped ZSiCNRs, the conductivity is significantly larger for Si atom substituted than that of C atom replacement. Besides, different temperature dependent conductivity characters are exhibited in the weak and strong ionization regions, indicating the differences in dominant factor for the transport processes. The temperature-dependent holes trapping rate of carrier recombination increased sharply for C or Si atom substitution, indicating a negative temperature-dependence of lifetime of non-equilibrium minority carrier for doped ZSiCNRs. Further, the non-equilibrium minority carrier lifetime is longer with small injection due to the presence of donor impurities in group-V doped ZSiCNRs.