Barrier Diodes Research Articles

Field management in NiO x /β-Ga2O3 merged-PIN Schottky diodes: simulation studies and experimental validation

In recent years, p-type NiO x has emerged as a promising alternative to realize kilovolt-class β-Ga2O3-based PN junction diodes. However, only a handful of studies could realize β–Ga2O3-based unipolar diodes using NiO x as a guard ring or floating rings. In this work, we investigate the device design of NiO x /β-Ga2O3 unipolar diodes using the technology computer aided design simulations and experimental validations. We show that a systematic electric field management approach can potentially lead to NiO x /β-Ga2O3 heterojunction unipolar diode and offer enhanced breakdown characteristics without a severe compromise in the ON-state resistance. Accordingly, the NiO x /β-Ga2O3 heterojunction diode in the merged-PIN Schottky configuration is shown to outperform the regular Schottky diode or junction barrier Schottky diode counterpart. The analysis performed in this work is believed to be valuable in the device design of β-Ga2O3-based unipolar diodes that use a different p-type semiconductor candidate as guard rings and floating rings.

Independently Accessible Dual-Band Barrier Infrared Detector Using Type-II Superlattices

We report a novel dual-band barrier infrared detector (DBIRD) design using InAs/GaSb type-II superlattices (T2SLs). The DBIRD structure consists of back-to-back barrier diodes: a “blue channel” (BC) diode which has an nBp architecture, an n-type layer of a larger bandgap for absorbing the blue band infrared/barrier/p-type layer, and a “red channel” (RC) diode which has a pBn architecture, a p-type layer of a smaller bandgap for absorbing the red band infrared/barrier/n-type layer. Each has a unipolar barrier using a T2SL lattice matched to a GaSb substrate to impede the flow of majority carriers from the absorbing layer. Each channel in the DBIRD can be independently accessed with a low bias voltage as is preferable for high-speed thermal imaging. The device modeling of DBIRDs and simulation results of the current–voltage characteristics under dark and illuminated conditions are also presented. They predict that the dual-band operation of the DBIRD will produce low dark currents and 45–56% quantum efficiencies for the in-band photons in the BC with λc = 5.58 μm, and a nearly constant 32% in the RC with λc = 8.05 μm. The spectral quantum efficiency of the BC for 500 K blackbody radiation is approximately 50% over the range of λ = 3–4.7 μm, while that of the RC has a peak of 42% at 5.9 μm. The DBIRD may provide improved high-speed dual-band imaging in comparison with NBn dual-band detectors.

Fabrication of n-ZnS/p-SnS, n-ZnO/p-SnS, and n-SnO2/p-SnS heterojunctions by 2-step SILAR process for photodetector applications

In this work, we present the fabrication and detailed analysis of three functional heterojunctions based on SnS. Unlike most of the previous reports, all semiconductor layers in the heterojunctions were deposited using the low-cost SILAR technique. The ZnS, ZnO, and SnO2 films, each with a thickness of 400 nm, were grown on a previously deposited 800 nm SnS layer, forming n-ZnS/p-SnS, n-ZnO/p-SnS, and n-SnO2/p-SnS heterojunctions. Current-voltage characteristics confirmed the successful formation of p-n junctions. Various models were used to estimate junction parameters such as diode ideality factor, barrier height, and series resistance. The fabricated diodes exhibited a prominent photo response under illumination. Photodetection figures of merit were estimated for all the devices. n-ZnS/p-SnS showed 0.003μA response current, with 0.27 sensitivity. The responsivity observed was around 0.6 μA /W with LDR of 2.09 dB. The specific detectivity was 106 Jones. Similarly, n-ZnO/p-SnS showed 0.021μA response current, with 0.38 sensitivity. The responsivity observed was around 4.2 μA /W with LDR of 2.80 dB. The specific detectivity was 106 Jones. However, n-SnO2/p-SnS showed remarkable figures of merit such as 2.4 μA response current, with 8.40 sensitivity. The responsivity observed was around 488 μA/W with LDR of 19.47 dB. The specific detectivity was 109 Jones. The rise and decay time of the photocurrent were 5 and 7 s, respectively.

Investigation of fundamental electrical and optoelectronic properties of an organic- and carbon-based MnPc/GC photodiode with high photosensitivity

The aim of this work is to provide an alternative to optoelectronic devices that use carbon and organic materials. To achieve this, we coated a modified MnPc organic semiconductor compound onto a graphite-like carbon (GC) thin film using the thermal evaporation technique, and fabricated an organic-based, highly light-sensitive MnPc/GC hybrid heterojunction. The heterojunction had a transmittance of approximately 60% in the visible region, an absorption coefficient of ∼106 m−1, and an energy band gap of 2.6 eV. Subsequently, Ag contacts were grown on the surface of each layer, and the Ag/MnPc/GC/Ag photodiode was subjected to fundamental electrical analysis at various light intensities and a ±3 V applied potential. Analysis in a dark environment revealed that the photodiode had a rectification ratio of 2.59 × 103, a series resistance of 28 Ω, and a shunt resistance of 4.17 × 104 Ω, as calculated from Ohm’s law. The diode ideality factor and barrier height of the photodiode were determined from thermionic emission theory to be 5.60 and 0.71 eV, respectively, and it was observed that these decreased with increasing light intensity. The photodetector parameters of the MnPc/GC hybrid photodiode were determined under positive and negative applied potentials at various light intensities. The highest photocurrent, photoconductive responsivity, photosensitivity, and specific detectivity were determined to be 1.512 × 10−1 A, 11.52 A.W−1, 9.83 × 105, and 2.48 × 1012 Jones, respectively, which were significantly higher than those reported in literature for organic and inorganic-based photodiodes. Based on the findings, it was concluded that the Ag/MnPc/GC/Ag photodiode holds promise as an alternative for sensors, solar cells, photodetectors, and optoelectronic communications applications.

Penentuan Resistansi Dinamis Pada Dioda Silikon 1n4002 Melalui Pengukuran Karakteristik Arus Terhadap Tegangan (I-V) Berbasis Arduino Mega 2560

An instrument for measuring I-V characteristics and determination of the dynamic resistance of a Silicon 1n4002 diode based on Arduino Mega 2560 has been successfully developed. This measurement was carried out by increasing the bias voltage periodically from 0 V to 5 V and observing the resulting forward voltage and forward current for each increase in the bias voltage. There is an increase in current when the diode voltage reaches 0.7 V, which is the diode barrier voltage. This happens if the limit resistor installed in the circuit is 100 Ω. The largest dynamic resistance value is 593.069 Ω, which is below the forward voltage of 0.6 V. Furthermore, the smallest dynamic resistance value is 2.293 Ω which is above the forward voltage of 0.7 V. The greater the value of the current flowing in the diode circuit, the smaller the dynamic resistance value of the diode and the smaller the value of the current flowing, the greater the dynamic resistance of the diode.

Photoresponse of the Al/n-Si Schottky diode with nanorod ZnO interface layer prepared by hydrothermal method

In this study, ZnO nanorods (ZnO-NR) were prepared on n-Si wafer by hydrothermal method. Structural and morphologic properties of ZnO nanostructures were investigated through XRD and SEM method. The illumination impacts on the current-voltage (I-V) measurements of the prepared Al/ZnO-NR/n-Si diode were explored in the dark and different illumination intensities (20–100 mW/cm2) between ± 1.5 V bias voltage range. The Schottky diode barrier height value had an increasing trend with increasing illumination intensity from 20 to 100 mW/cm2 while the ideality factor had a decreasing trend with the increase of photocurrent. The temporary photocurrent increases as illumination intensity increases. The slope (α) of the logI_ph-logP curve was obtained as 0.618 and this slope confirmed that this ZnO nanorod shows photoconducting behavior. The short-circuit current (I_sc) and open-circuit voltage (V_oc) values were obtained to be 774.08 μA and 0.24 V under 100 mW/cm2 illumination intensity, respectively. It was concluded that the prepared Al/ZnO-NR/n-Si diode can be used in the optoelectronic applications, especially for the photodiode industry.

Fabrication and morphological, optical, and electrical characterisation of Cu-doped ZnO nanorod/coronene nanowire hybrid heterojunctions

The electrochemical deposition technique was employed to grow 1% and 3% Cu-doped ZnO nanorods on glass/ITO substrate. Then, coronene nanowire was deposited on the 1% and 3% Cu-doped ZnO surfaces via the thermal evaporation technique as an interfacial layer of hybrid heterojunctions. Structural analyses of different ratios of the Cu-doped ZnO layers revealed that they contain ZnO, CuZn, Cu2O and Cu16O14.15 phases, and further that a monoclinic coronene crystal structure could be detected from the XRD spectrum of ITO/coronene thin film. The elemental composition of the1% and 3% Cu-doped ZnO layers was investigated via SEM-EDX from which it was observed that the proportions of the elemental weight of Zn, O, and Cu were 73.4%, 23.5% and 3.1%, respectively, for 1% Cu- doped ZnO, and 71.2%, 21.1%, 7.7% for 3%Cu-doped ZnO. The surface morphological analyses revealed that the inorganic layer crystallised as hexagonal pillar nanorods and the organic layer as nanowires. It was also observed that the nanorod thickness increased from 130–230 nm to 270–450 nm with increasing Cu ratio. As a result of the optical analyses of the hybrid heterojunctions, it was found that the maximum absorption region of the heterojunctions was in the near-ultraviolet region and that they had very low transmittances (0.6%–0.77%). In addition, the absorption coefficients and the band gap energy were ≈ 107 (m−1) and were 3.09–3.25 eV, respectively, while the band gap energy of coronene thin film on ITO was 2.90 eV. Electrical analyses of Ag/ZnO:1%Cu/coronene/Ag and Ag/ZnO:3%Cu/coronene/Ag heterojunctions were performed in the ±0.4 V potential range in a dark environment at room temperature, and diode parameters were determined using various methods. It was found that Ag/ZnO:1%Cu/coronene/Ag and Ag/ZnO:3%Cu/coronene/Ag diodes had high rectification ratios with the values of 250 and 1140, respectively. It is also obvious that while the increase in Cu doping ratio increased the diode ideality factor, series resistances and barrier heights ranged from 1.31 to 13.7, 17 to 3283 Ω, and 0.43 to 0.55 eV, respectively, it decreased the reverse saturation current from 8.1 × 10–3 A to 8.2 × 10–5 A.

Метод построения МИС СВЧ ограничителей мощности для повышения порога сгорания

The article shows the method of constructing the MMIC power limiter. The purpose of this research is to increase the burnout level. We considered a classical two-stage cir-cuit on anti-parallel p-i-n diodes. The idea of increasing the burnout level is to redis-tribute currents, so that at the burnout power at the first and second stages, the current is equal to the saturation current – 0.41–0.45 A / 100 µm. To do this, a simulation of the circuits was carried out – the ratio of the capacity of the first to the second stage 1:1, 2:1, 3:1 and 4:1. The design circuits were manufactured at p-i-n diode GaAs tech-nology of JSC RPC “Istok” named after Shokin, the height of the diode barrier is 1,1 V / 1 mA, the breakdown voltage is 45 V / 100 µA. The results of probe measurements S-parameters of power limiters and measure-ments of dynamic characteristics in the fix-ture are presented. Devices in the frequency range from 1 GHz to 16 GHz have losses less than 0.8 dB and VSWR input and output less than 2. The burnout level in continu-ous power at a frequency of 10 GHz was: for topology 1:1 — 45.3 dBm, 2:1 — 48.3 dBm and for topology 3:1 — 49.6 dBm. Under the same conditions, serial MMIC power limiters of foreign company were investigated. The burnout power density was ~20 W / 100 µm of the periphery, for the JSC RPC “Istok” named after Shokin technology, which exceeds the level of the investigated foreign analogues.

Fabrication and characterization of novel Ga-doped WO3 films and n-Ga@WO3/p-Si junction diode for optoelectronic device applications

In this work, we have fabricated the gallium doped tungsten trioxide (Ga@WO3) films and n-Ga@WO3/p-Si diodes by taking various concentrations (0, 3, 6, 9, and 12 wt%) of Ga through the spin-coating method. To analyze the impact of Ga-dopant on the physical properties of WO3 films, XRD, SEM, and robust dc electrical analyses have been used. From the XRD analysis, compared to the lower concentration of Ga dopant, the higher dopant concentrations show the presence of Ga on the o-GaWO3 crystal structure. The nanoplates-like surface morphology was detected by SEM analysis. The temperature-dependent dc conductivity was studied by I-V characterization, and 12 wt% of Ga doped WO3 thin film exhibits a higher conductivity value and low activation energy (Ea) at room temperature. The J-V nature signifies that n-WO3/p-Si diode performance was enhanced using Ga dopant concentration. The diode constraints ideality factor (n) and barrier height (ΦB) values were determined from J-V, Cheung’s, and Norde's functions. From J-V-T & Richardson plot (ln (J0/T2)), we obtain that the ΦB values were decreased with decreasing temperature. This is explained through the mechanism of thermionic emission with ΦB Gaussian distribution. The determined parameters of the fabricated films and junction diode signify that these can be employed in the applications of photodetectors and solar cells.

Fabrication and transport properties of thermally evaporated cadmium selenide thin films for photovoltaic applications

The present research article reports the fabrication and transport properties of Au/n-CdTe Schottky diode prepared by the thermal evaporation technique. The microstructural examination of CdTe thin film was carried out using transmission electron microscopy (TEM). The diode was endangered to current (I)-voltage (V) and capacitance (C)-voltage (V) characterization using a computer-controlled semiconductor characterization system (SCS-4200) in dark surroundings. The activation and bandgap energies of n-CdTe were determined by plotting DC electrical resistance (R) variation with temperature (T). The I-V analysis of pristine Schottky diode showed rectifying behaviour, and the diode' possible conduction mechanisms were determined. The diode ideality factor, barrier height and carrier concentration were derived accordingly. A theoretical energy band diagram was constructed for the Au/n-CdTe Schottky diode-based Anderson's model. The photovoltaic behaviour of the fabricated Schottky diode was investigated, and results are reported. The implications are discussed.

A remarkable effect of substrate temperature on novel Al/Y2O3/n-Si heterojunction diodes performance fabricated by facile jet nebulizer spray pyrolysis for optoelectronic applications

Herein, we present the development and characterization of Yttrium oxide (Y2O3) films and Al/Y2O3/n-Si heterojunction diodes at various substrate temperatures using a low-cost facile jet nebulizer spray pyrolysis (JNSP) technique. The X-ray powder diffraction (XRD) pattern proved polycrystalline films of Y2O3 with a cubic structure. Field emission scanning electron microscope (FESEM) images reveal very fine nanograins formation in Y2O3 films at all temperatures. Scanning probe microscopy (SPM) analysis shows very low roughness of all films. The detailed compositional/homogeneity analysis was done via energy dispersive X-ray (EDX)/e-mapping analysis. All the films exhibited a sharp absorption edge at ∼ 280 nm, and the estimated energy gap values were noticed between 4.5 to 4.9 eV. Moreover, the observed photoluminescence (PL) spectrum indicated number of emission peaks in the grown films. From the current – voltage (I-V) characteristic, the calculated ideality factor (n) value was noticed to be drastically reduced from 7.66 to 2.87 on increasing the substrate temperature. Further, the diode ideality factor, series resistance (Rs) and barrier height (ФB) were obtained from Cheung's method. The results revealed that the developed Al/Y2O3/n-Si heterojunction diode is a promising contender for optoelectronic devices.

Ruthenium (III)–pyridine complex: Synthesis, characterization, barrier diode and photodiode applications in Al/Ru-Py/p-Si/Al sandwich device structure

Ruthenium (III)–pyridine complex: Synthesis, characterization, barrier diode and photodiode applications in Al/Ru-Py/p-Si/Al sandwich device structure

Electronic and photovoltage performance of TTBTP/n-Si heterojunctions for possible use in solar cell

Fabrication, structural and electrical characterization of 2,7,12,17-tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphine (TTBTP) films for their application in photovoltaic device have been investigated. The atomic force microscopy showed that our synthesized film has an average grain size and roughness of 152 nm and 31.35 nm, respectively. The capacitance-voltage and current density-voltage characteristics of TTBTP/n-Si heterojunction (HJ) have been extensively researched. The TTBTP/n-Si HJ thin film was characterized by a contact barrier of 0.70 eV and a rectification ratio of 663 at 300 K. The conduction mechanisms and the fundamental diode parameters, for example, series resistance, ideality factor, and barrier height are calculated. The fabricated diode parameters show a temperature dependency in the temperature range of 300–383 K. Under the light, the TTBTP/n-Si HJ demonstrates photovoltage conduct from which the photovoltaic parameters are assessed. The open-circuit voltage, short circuit current, and power conversion efficiency are evaluated as 0.68 V, 8.06 mA/cm2, and 2.38%, respectively.

Impact of Ar+ bombardment of 4H–SiC substrates on Schottky diode barrier heights

In this paper, we investigate the impact of plasma power and plasma exposure time on the Schottky barrier height (SBH) and the ideality factor of silicon carbide (SiC) Schottky diodes. N-doped 4H–SiC Schottky diodes with molybdenum nitride (MoN) top metallization are fabricated. The plasma power PISE is varied from 0 up to 300 W at a constant plasma time of 300 s. High resolution transmission electron microscopy is performed showing a ~6 nm thin amorphous layer formed at the MoN/4H–SiC interfaces after ion bombardment. Current-Voltage-Temperature measurements are conducted in a wide temperature range from 50 K up to 500 K. SBHs are extracted using standard techniques, showing a significant influence of PISE on the SBH. A SBH of about 1 V is measured for diodes without ion pretreatment (PISE = 0 W). The highest SBH of 1.1 V is extracted for the diode with PISE = 50 W, followed by a continuous decrease of the SBH at higher plasma powers. At a PISE = 300 W, a SBH of 1.02 V is obtained, which is close to the SBH at PISE = 0 W. These results show that, ion bombardment increases the SBH. However, similar SBHs can be obtained by optimizing the plasma power when ion bombardment is required. Additionally, the plasma time is varied from 0 s up to 420 s by simultaneously holding the plasma power constant at 300 W. The activation energy of the investigated Schottky diodes is extracted from Arrhenius plots obtained at different voltages from −1 to −5 V. These results are in good agreement SBH evaluation. The influence of ion bombardment on SBH homogeneity on wafer level is presented. It is shown that the standard deviation of SBH on 4-inch wafers can be reduced by a factor of 2.7 when ion bombardment is used, compared to diodes fabricated without ion bombardment.

Structural, optical and junction characteristics of pyrazolo pyridine derivatives

Two pyridine derivatives, 6-(2-chlorophenyl)-2,3-dihydro-1-methyl-3-oxo-2-phenyl-1H-pyrazolo[4,3-b]pyridine-5-carbonitrile (C1) and 6-(4-chlorophenyl)-2,3-dihydro-1-methyl-3-oxo-2-phenyl-1H-pyrazolo[4,3-b] pyridine-5-carbonitrile (C2) are prepared and characterized. Different techniques were applied to confirm their molecular structures. The thermal, structural, optical and diode characteristics of the two pyridine derivatives are reported. X-ray diffraction (XRD) patterns of C1 and C2 in powder form reveal monoclinic polycrystalline nature. The optical functions of C1 and C2 films are calculated from the transmittance and reflectance spectra measured over the spectral range 200–2500 nm. Two indirect allowed optical energy gaps were estimated; 2.55 and 3.13 eV for C1 and 2.7 and 3.27 eV for C2. Thin films of the two compounds were deposited onto p-Si substrates for fabricating heterojunctions. The diode ideality factor and barrier height of both devices were calculated. In addition, Norde's function was used to determine the important parameters of the devices. At relatively high voltage, the conduction mechanism is described by space charge limited current in both devices. The conduction of the device based on C1 and C2 compounds are due to pool–Frenkel and Schottky mechanisms. The data at reverse biasing are also analyzed and estimated. The device based on C1 compound did not give any response to light, while that based on C2 can used as photosensor.

The Research of Piezo Phototron Effect in A2B6 Film Structures

The paper presents the results of the study of a piezo phototron effect in hetero structures based on A2B6 films. The field of study of the piezo phototron effect in semiconductor thin films is new. The use of materials that have several properties at the same time, namely semiconductors, piezoelectrics and photoelectric properties, allows us to create a fundamentally new class of semiconductor devices, especially in the field of sensors and photovoltaics. Obtaining films of the A2B6 group, which include CdS, CdTe, CdSe, ZnS, ZnSe, ZnO with an existing piezoelectric effect, is an urgent task. In this work, the object of study is diode structures based on them. Namely, CdS films were grown by thermal evaporation on a flexible molybdenum substrate. A thin layer of degenerate CuxS semiconductor was deposited on top of the CdS films, which allowed it to form a diode barrier structure. For the study of photodiode properties, measurements were made of the current-voltage characteristics (VAC) in the dark and light modes. Measurements were made using a power source, a voltmeter and an ammeter. The limits of voltage measurements ranged from -2 V to 2 V to prevent possible breakdown of structures. A white LED with a power output of 30mW / cm2 was used as the light source. From the obtained CVCs it was obtained that a rectifying barrier is formed between the semiconductor films and the structure has a diode characteristic. The magnitude of the reverse current increases during illumination. Pressure was applied to the diode structures to investigate the piezoelectric effect. The pressure applied to the sample was changed by means of levers weighing 10, 20, 50, 100 and 200 grams. As a result of the measurements of the CVC during the application of pressure, it was found that the current on the forward and reverse branches of the CVC showed an increase in both the dark mode of measurement and in the light. This indicates the presence of a piezoelectric effect in this heterojunction. The calculated values of the sensitivity to pressure showed that the current on the back and forward branches of the CVC changes at different intervals. The highest sensitivity in the range 0–77.31 absolute units is observed for reverse current without illumination. With additional illumination, the sensitivity to the pressure on the back branch of the CVC decreases and is 0–7.73. All measurements made show the presence of a piezophototron effect, which allows the creation of new functional devices for measuring pressure and luminance based on this heterojunction.

Simulation Study of a Novel Snapback Free Reverse-Conducting SOI-LIGBT With Embedded P-Type Schottky Barrier Diode

In this article, a novel reverse-conducting lateral insulated gate bipolar transistor (RC-LIGBT) with embedded diode and p-type Schottky Barrier Diode (p-SBD) is proposed. The two diodes are connected in series through a floating electrode, which provides a current path for carriers in reverse-conducting mode. Compared with the Separated Shorted-Anode RCLIGBT (SSA-RC-LIGBT), the proposed structure not only eliminates the snapback voltage ( $\Delta {V}_{\text {SB}}$ ) but also avoids the waste of device area. Therefore, the superior reverse recovery characteristics and excellent tradeoff relationship between ON-state voltage ( ${V}_{ \mathrm{\scriptscriptstyle ON}}$ ) and turn-off loss ( ${E}_{ \mathrm{\scriptscriptstyle OFF}}$ ) are obtained. The reverse recovery charge of the proposed RC-LIGBT shows 43.9% and 63.2% reduction compared with those of the SSA-RC-LIGBT with ${L}_{\text {B}}$ (distance between the p+ collector and the shorted n+ collector) being 34 and $64~\mu \text{m}$ , respectively. The turn-off loss of the proposed RC-LIGBT at ${V}_{ \mathrm{\scriptscriptstyle ON}} = {2.6}$ V is reduced by 68.2% and 87.1% compared with those of the SSA-RC-LIGBT with $\sf \Delta {V}_{\text {SB}} = {0.48}$ V and $\sf \Delta {V}_{\text {SB}} = {0.17}$ V, respectively. Moreover, the proposed RC-LIGBT has a self-adjusted collector injection efficiency under different temperatures to dramatically improve the Short Circuit Safe Operation Area (SCSOA).

Hot electron effects on the operation of potential well barrier diodes

A study has just been carried out on hot electron effects in GaAs/Al0.3Ga0.7As potential well barrier (PWB) diodes using both Monte Carlo (MC) and drift-diffusion (DD) models of charge transport. We show the operation and behaviour of the diode in terms of electric field, mean electron velocity and potential, mean energy of electrons and Γ-valley population. The MC model predicts lower currents flowing through the diode due to back scattering at anode (collector) and carrier heating at higher bias. At a bias of 1.0 V, the current density obtained from experimental result, MC and DD simulation models are 1.35, 1.12 and 1.77 μA/μm2 respectively. The reduction in current over conventional model, is compensated to a certain extent because less charge settles in the potential well and so the barrier is slightly reduced. The DD model results in higher currents under the same bias and conditions. However, at very low bias specifically, up to 0.3 V without any carrier heating effects, the DD and MC models look pretty similar as experimental results. The significant differences observed in the I–V characteristics of the DD and MC models at higher biases confirm the importance of energy transport when considering these devices.

Modeling Of Energy-Band Diagram for Plasma-Metal Junction

Plasma based technologies find wide technological applications. The theory for electrical properties of plasma is well established, for different systems including simple dc discharges to complex fusion machines, using fluid model and statistical model. However, there are still several areas that are unexplored and one of such topics is plasma-material interaction. In present investigation we propose the concept of energy band diagram for plasma-metal junction analogous to the energy band diagram of P-N junction. The I-V characteristics of P-N junction diode and Schottky barrier diode are explained using well established energy band theory. In this work the concept of energy-band diagram for plasma-metal junction has been introduced and concentrates on how the I-V characteristics of plasma-metal junction vary for metals with different work functions. Using the proposed energy band diagram, I-V characteristics of plasma-metal junction obtained numerically. The I-V characteristics obtained using this concept of energy-band diagram of plasma-metal junction is consistent with theory and therefore this concept may have wide impact on laboratory plasmas and may provide a new method for higher accuracy for experimental measurements.

Detectors Based on Low-Barrier Mott Diodes and Their Characteristics in the 150–250 GHz Range

The characteristics of millimeter-wavelength detectors based on planar Mott diodes with near-surface δ-doping operating without a constant bias are discussed. These detectors have a volt–watt sensitivity of ~1000 V/W with NEP ~ 10 pW/Hz1/2 in the 150–250 GHz range. The obtained estimates reveal the possibility of an additional order-of-magnitude enhancement of the performance characteristics of detectors with smaller areas of the diode barrier contact.