- 标题
- 摘要
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- 实验方案
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Determination of physical mechanism responsible for the capacitance-voltage weak inversion “hump” phenomenon in n-InGaAs based metal-oxide-semiconductor gate stacks
摘要： Weak inversion capacitance-voltage (C-V) “hump” is a widely observed phenomenon at n-InGaAs based metal oxide semiconductor (MOS) structures. The mechanism responsible for this phenomenon is still under discussion. The C-V hump can be explained as an interaction of interface states with either one or both semiconductor energy bands. Each of the proposed mechanisms leads to a different interpretation of C-V hump. Simulating the mechanisms by relevant equivalent circuits, the capacitance and conductance characteristics of the MOS structure were calculated and compared with experimental results. The mechanism responsible for the C-V hump was determined.
关键词： interface states,equivalent circuits,n-InGaAs,metal-oxide-semiconductor,capacitance-voltage hump
更新于2025-11-14 17:28:48
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Current linearity and operation stability in Al <sub/>2</sub> O <sub/>3</sub> -gate AlGaN/GaN MOS high electron mobility transistors
摘要： To investigate current linearity and operation stability of metal–oxide–semiconductor (MOS) AlGaN/GaN high electron mobility transistors (HEMTs), we have fabricated and characterized the Al2O3-gate MOS-HEMTs without and with a bias annealing in air at 300 °C. Compared with the as-fabricated (unannealed) MOS HEMTs, the bias-annealed devices showed improved linearity of ID–VG curves even in the forward bias regime, resulting in increased maximum drain current. Lower subthreshold slope was also observed after bias annealing. From the precise capacitance–voltage analysis on a MOS diode fabricated on the AlGaN/GaN heterostructure, it was found that the bias annealing effectively reduced the state density at the Al2O3/AlGaN interface. This led to efficient modulation of the AlGaN surface potential close to the conduction band edge, resulting in good gate control of two-dimensional electron gas density even at forward bias. In addition, the bias-annealed MOS HEMT showed small threshold voltage shift after applying forward bias stress and stable operation even at high temperatures.
关键词： current linearity,interface states,MOS-HEMT,AlGaN/GaN,operation stability,bias annealing
更新于2025-09-23 15:23:52
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Lateral interfaces of transition metal dichalcogenides: A stable tunable one-dimensional physics platform
摘要： We study in-plane lateral heterostructures of commensurate transition-metal dichalcogenides, such as MoS2-WS2 and MoSe2-WSe2, and find interfacial and edge states that are highly localized to these regions of the heterostructure. These are one-dimensional (1D) in nature, lying within the band gap of the bulk structure and exhibiting complex orbital and spin structure. We describe such heteroribbons with a three-orbital tight-binding model that uses first principles and experimental parameters as input, allowing us to model realistic systems. Analytical modeling for the 1D interfacial bands results in long-range hoppings due to the hybridization along the interface, with strong spin-orbit couplings. We further explore the Ruderman-Kittel-Kasuya-Yosida indirect interaction between magnetic impurities located at the interface. The unusual features of the interface states result in effective long-range exchange noncollinear interactions between impurities. These results suggest that transition-metal dichalcogenide interfaces could serve as stable, tunable 1D platform with unique properties for possible use in exploring Majorana fermions, plasma excitations, and spintronics applications.
关键词： spin-orbit coupling,interface states,transition metal dichalcogenides,RKKY interaction,tight-binding model,lateral heterostructures
更新于2025-09-23 15:23:52
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A comprehensive study on the interface states in the ECR-PECVD SiO2/p-Si MOS structures analyzed by different method
摘要： The electrical properties of SiO2/p-Si films deposited by ECR-PECVD were studied at different frequencies (100-1 MHz) and gate voltages (-6–3 V). Results showed a frequency dispersion of C-Vg and G/ω-Vg. With increasing frequency, the capacitance and conductance are strongly decreased. An apparent peak in the depletion regime of the G/ω-Vg plots can be attributed to the existence of density Nss at Si/SiO2. The (Nss)value vary from 1.5 × 10^12 to 0.5 × 10^11 eV^-1 cm^-2, it has been determined by High-Low frequency capacitance technic. The Nss- Vg curve presents a peak at about -3 V, suggesting the presence Nss between the (Si)/SiO2 interface. Hill and Coleman method shows that the Nss decreases with increasing frequency which explains the high value of capacitance at low frequency. The Nss and their relaxation time τ by the conductance method ranged from 1.8 × 10^13 to 1.37 × 10^11 eV^-1 cm^-2 and 5.17 × 10^-7 to 8 × 10^-6 s, in the range (0.189-Ev) and (0.57- Ev) eV, respectively. The Nss was responsible for the non-ideal behavior of C-Vg and G-Vg leading to the breakdown of such device. Comparing the three method results show that parallel conductance is very precise and accurate.
关键词： Capacitance method,Relaxation time,Frequency,Interface states,Metal/Oxide/Semiconductor (MOS),Conductance method
更新于2025-09-23 15:23:52
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Interfacial passivation of n-ZnO/p-Si heterojunction by CuI thin layer
摘要： The ZnO/Si heterojunction diode can be integrated with the Si process, which has attracted great attention in recent years. However, the large number of interface states at the ZnO/Si heterojunction interface could adversely affect its optoelectronic properties. Here, n-type ZnO thin film was deposited on p-Si substrate for formation of an n-ZnO/p-Si heterojunction substrate. To passivate the ZnO/Si interface, a thin CuI film interface passivation layer was inserted at the ZnO/p-Si heterojunction interface. Electrical characterization such as I–V and C–V characteristic curves confirmed the significant improvement of the heterojunction properties e.g. enhancement of forward current injection, reduction of reverse current and improvement of the rectification ratio. These results showed that the passivation of interface is critical for ZnO/Si heterojunctions.
关键词： CuI,heterojunction,interface states,electrical properties,ZnO/p-Si
更新于2025-09-23 15:23:52
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Photo-induced effects in organic thin film transistors based on dinaphtho [2,3-b:2′,3′-f] Thieno[3,2-b′] thiophene (DNTT)
摘要： We have investigated the photoresponse of organic thin film transistors (OTFTs) based on evaporated films of dinaphtho [2,3-b:2',3'-f] thieno[3,2-b'] thiophene (DNNT) as the active semiconductor and spin-coated polystyrene as the gate insulator. Both during illumination and in subsequent measurements in the dark after long periods under illumination, transfer characteristics shift to more positive gate voltages. The greatest photoresponse was achieved at 460 nm, near the absorption maximum of DNTT. The maximum photosensitivity and photoresponsivity measured were ~104 and 1.6 A/W respectively. The latter is the highest reported for an organic semiconductor on a polymeric gate insulator and by suitable adjustments to device geometry could be increased to match the highest reported, ~105 A/W, for organic semiconductors. Weaker responses were also obtained when exposed to light from the long-wavelength tail in the absorption spectrum. At these longer wavelengths, the response arises entirely from a shift in flatband voltage caused by deep interface trapping of photo-generated electrons. At 460 nm, however, the positive shift, D VON, in turn-on voltage is much greater than D VT suggesting that ~3.5 x 1011 electrons/cm2 are trapped at the interface at the start of the gate voltage sweep, but ~60% are neutralised by holes from the channel as the device begins to turn on. While the resulting change in subthreshold slope could be interpreted as a change in the density of states (DoS) in the DNTT, this is discounted. Gate bias stress measurements made under illumination, reveal that positive bias enhances interface electron trapping while negative bias reduces the effect owing to the simultaneous trapping of holes from the accumulation channel.
关键词： OTFT,DNTT,Interface States,Photosensitivity
更新于2025-09-23 15:21:01
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The analysis of the electrical characteristics and interface state densities of Re/n-type Si Schottky barrier diodes at room temperature
摘要： The main electrical characteristics of current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature of the Re/n-type Si Schottky barrier diodes prepared by pulsed laser deposition (PLD) method have been examined. The values of the basic electrical properties such as forward saturation current (Io), ideality factors (n), barrier heights (Фbo), recti?cation ratio (RR) and series resistances (RS) were obtained from I-V and C-V measurements using di?erent calculation methods. At low voltages (V ≤ 0.3 V), the electrical conduction was formed to take place by thermionic emission, whereas at high voltages (V > 0.3 V), a space charge limited conduction mechanism was shown. Furthermore, the interface state densities (NSS) as a function of energy distribution (ESS- EV) was obtained from the I-V data by taking into account the bias dependence of the e?ective barrier height (Φb) for the Re/n-type Si Schottky barrier diodes.
关键词： interface states,surface potential,recti?cation ratio,Electrical parameters,series resistance
更新于2025-09-23 15:21:01
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Numerical simulation for optimization of an ultra-thin n-type WS2/p-type c-Si heterojunction solar cells
摘要： Recently, ultra-thin tungsten disul?de (WS2) has become one of the hot spots in the research of solar cell materials due to its excellent optical and electrical properties. In this study, we use AFORS-HET software version 2.5 at air mass 1.5 to simulate the structure of n-type WS2/p-type c-Si heterojunction solar cells. Our goal is to ?nd an appropriate way to improve the performance of n-type WS2/p-type c-Si heterojunction solar cells by simulation. Through optimizing the parameters of both WS2 layer and Si layer, we obtain a maximum photovoltaic conversion e?ciency of 20.57%. Subsequently, we investigate the in?uence of the ITO work function and the interface states on the performance of n-type WS2/p-type c-Si heterojunction solar cells. It’s found that through selecting the suitable ITO work function and decreasing the interface defect density, solar cell’s performance can be further improved. Our result indicates that ultra-thin WS2 is a promising photovoltaic material for the application in solar cells.
关键词： Work function,Heterojunction solar cells,Numerical simulation,Tungsten disul?de,Interface states
更新于2025-09-23 15:19:57
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Enhanced Performances of p-Si/n-ZnO Self-powered Photodetector by Interface State Modification and Pyro-phototronic Effect
摘要： ZnO based self-powered photodetector (PD) has great application potential in distributing sensor networks and internet of things. However, a large number of surface or interface states within ZnO limit its performance improvement. Here, the surface and interface states of ZnO is greatly eliminated by ultraviolet irradiation as an interfacial modification engineering. Reduction of interface states reduces ohmic resistance, also enhances the tuning role of pyro-phototronic effect. And the transient response currents of the self-powered PD are thus significantly improved with a maximal enhancement factor of more than 5900% for the 325-785 nm broadband stimulating beams. The corresponding response time is decreased to few milliseconds or sub-milliseconds. The results indicate that surface-state reduction of ZnO can effectively enhance the modifying role of pyro-phototronic effect and greatly improve the response performances of the self-powered broadband PDs with great application demands in Internet of things, broad spectral detecting and imaging, and smart optoelectronic devices.
关键词： Self-powered,ultraviolet irradiation,interface states,pyro-phototronic effect,broadband photodetectors
更新于2025-09-23 15:19:57
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Electrical characterization of two analogous Schottky contacts produced from <i>N</i> -substituted 1,8-naphthalimide
摘要： The aim of this study was to analyze the interface states (Nss) in pure Al//p-Si/Al, Al/N-F Nft/p-Si/Al and Al/N-T Nft/p-Si/Al Schottky barrier diodes (SBDs). N-Substituted 1,8-naphthalimide thin films were deposited on a p-Si substrate by spin coating and annealed at B200 1C for 60 s under an air atmosphere. Al contacts were obtained via reactive magnetron sputtering. The current voltage (I–V) characteristics of the SBDs were measured at room temperature. From the I–V characteristics, the SBDs ideality factor (n) and zero-bias barrier height values (Fb) of 1.27, 1.00, and 1.05 and 0.66 eV, 0.70 eV, and 0.64 eV were observed for the Al//p-Si/Al, Al/N-F Nft/p-Si/Al and Al/N-T Nft/p-Si/Al Schottky barrier diodes, respectively. The interface state density distribution profile (Nss) as a function of (Ess–Ev) was extracted from the forward-bias I–V measurements by considering the effective barrier height and (Fe) and series resistance (Rs) of the Schottky diode. The obtained Nss plot tendency showed that the existence of interface states has no significant effect on the rectifying and capacitance characteristics. The Nss values with the 1,8-naphthalimide layer were lower than that without it. This shows that naphthalimide exhibits a strong contribution by blocking the unwanted states and some traps in the conduction mechanism, which may cause possible cracks or deep paths for carriers to travel along the junction.
关键词： magnetron sputtering,interface states,Schottky barrier diodes,spin coating,1,8-naphthalimide
更新于2025-09-23 15:19:57