Solar-blind photodetection and photoconductive gain >50 corresponding to a responsivity >8 A/W were observed for β-Ga2O3 Schottky photodiodes. The origin of was investigated. Current-voltage characteristics the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as source gain. However, photocapacitance measurements indicated mechanism hole localization above-band gap illumination, suggesting self-trapped formation. Comparison...

Unlike the Si-SiO2 interface, SiC-SiO2 interface has large defect densities. Though nitridation been shown to reduce density, effect of H remains an open issue. Here we combine experimental data and results first-principles calculations demonstrate that a Si-C-O bonded interlayer with correlated threefold-coordinated C atoms accounts for observed states, passivation by N atomic H, nature residual defects.

The direct impact of the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /4H-SiC interface state density ( <i xmlns:xlink="http://www.w3.org/1999/xlink">D</i> xmlns:xlink="http://www.w3.org/1999/xlink">it</sub> ) on channel mobility lateral field-effect transistors is studied by tailoring trap distribution via nitridation thermal gate oxide. We observe that scales like inverse charged density, which consistent with...

Low interface trap density and high channel mobility on nonpolar faces of 4H-SiC, such as the (11[2̅]0) a-face, are fundamental importance in understanding SiC MOS devices. It is also critical for high-voltage trench power MOSFET development. We report new results passivation SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /a-face 4H-SiC using phosphorus, yielding field effect ~125 cm /V · s. revisit conventional NO passivation,...

Phosphorous from P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> is more effective than nitrogen for passivating the 4H-SiC/SiO interface. The peak value of field-effect mobility 4H-SiC metal-oxide-semiconductor transistors (MOSFETs) after phosphorus passivation approximately 80 cm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s. However, converts SiO layer to...

In this paper, the temperature dependence of turn-on characteristics Schottky barrier diodes fabricated on oriented n-type β-Ga2O3 is reported. The height (qΦbn) and ideality factor (n) for Ni- was found to be 1.08 ± 0.05 eV 1.19 respectively at room temperature. effective Richardson constant (A **) determined 42.96 A cm−2 K−2, in close agreement with theoretical value. At low temperatures (85–273 K), current–voltage reveal a strong heights factors corresponding deviation from extracted...

We report on the concentration, chemical bonding, and etching behavior of N at SiC(0001)/SiO2 interface using photoemission, ion scattering, computational modeling. For standard NO processing a SiC MOSFET, sub-monolayer nitrogen is found in thin inter-layer between substrate gate oxide (SiO2). Photoemission shows one main related core-level peak with two broad, higher energy satellites. Comparison to theory indicates that assigned bound three silicon neighbors, second nearest neighbors...

Channel mobility of >100 cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}$ </tex-math></inline-formula> V notation="LaTeX">$^{-1}$ s has been obtained on enhancement mode 4H-SiC MOSFETs using an antimony (Sb) doped surface channel in conjunction with nitric oxide (NO) postoxidation annealing. Temperature dependence the indicates that Sb, being n-type dopant, reduces electric field while NO anneal...

The electrical properties of interfaces and the impact post-deposition annealing have been investigated in gate oxides formed by low pressure chemical vapor deposition (LPCVD SiO2) atomic layer (Al2O3) on (2¯01) oriented n-type β-Ga2O3 single crystals. Capacitance-voltage based methods used to extract interface state densities, including densities slow ‘border’ traps at dielectric-Ga2O3 interfaces. It was observed that SiO2-β-Ga2O3 has a higher border trap density than Al2O3-β-Ga2O3. An...

The 4H–SiC/SiO2 interface is a major obstacle that hampers SiC device applications. nature of the transition region stoichiometry and structure need to be elucidated both understand improve such devices. In this paper, we use medium energy ion scattering on grade structures examine critical aspects dielectric/semiconductor structure. Our findings indicate no excess C greater than 1.8×1014 cm−2 from oxide surface down few monolayers beneath SiC/SiO2 interface, setting limits previously...

The collection and transport of charges at the electrodes are main factors limiting efficiency organic solar cells. Zinc oxide (ZnO) in nanostructured form helps to overcome this problem by introducing a ZnO buffer layer between photoanode donor material. To achieve this, thin film must exhibit good crystallinity, along with electrical conductivity high optical transparency visible range. aim work is investigate effect precursor sources concentrations on structural, morphological, properties...

Proton irradiation is used to probe the physics of 4H-silicon carbide (SiC) Schottky barrier diodes (SBDs) and negative channel metal oxide semiconductor (nMOS) capacitors for first time. Both 4H-SiC SBD SiC MOS structures show excellent radiation tolerance under high-energy, high-dose proton exposure. Unlike JBS diodes, which a strong increase in series resistance after irradiation, these SBDs very little forward bias I--V degradation exposure 63.3 MeV protons up fluence 5/spl times/10/sup...

Generation lifetimes and interface state densities of n-type 4H-SiC metal oxide semiconductor (MOS) capacitors are characterized by using the pulsed MOS capacitor technique. A decrease in lifetime increase density occurs when devices negatively biased at 400°C. This behavior is consistent with an effect seen Si∕SiO2 known as negative bias temperature instability. portion degradation caused this can be recovered removing well positively biasing device.

Biocompatible solid electrolyte chitosan is introduced as a protonic/electronic electric double layer (EDL) dielectric in multilayer MoS 2 transistor. This chitosan‐bioinspired transistor can operate at low working voltage (&lt;3 V) and exhibits an asymmetric ambipolar behavior. A high on/off ratio (∼10 4 ) was achieved for both electrons holes, conjunction with very steep subthreshold swing (67 mV/dec) which close to the theoretical limit of ideal field‐effect (60 mV/dec). It established...

Post-oxidation anneals that introduce nitrogen at the SiO2/4H-SiC interface have been most effective in reducing large trap density near 4H-SiC conduction band-edge for (0001) Si face 4H-SiC. Herein, we report effect of nitridation on interfaces created (11 20) a-face and C-face Significant reductions (from &gt;1013 cm-2 eV-1 to ~ 1012 EC-E ~0.1 eV) were observed these different interfaces, indicating presence substantial susceptible defects all crystal faces. Annealing nitridated hydrogen...

Proton irradiation-induced effects on AlGaN/GaN high electron mobility transistors (HEMTs) were studied by emulating a certain space radiation environment (upstream of the earth's bow shock) using relatively low energy (100 keV) proton beam with fluences 1 × 1010, 1012, and 1014 protons/cm2. In order to isolate radiation-induced produced modification epi-layer from change in device structure (such as contacts), epi-layers irradiated prior fabrication, followed material/device...

The channel conduction in 4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs) are highly impacted by charge trapping and scattering at the interface. Even though nitridation reduces interface trap density, still plays a crucial role increasing resistance these transistors. In this work, dominant mechanisms distinguished for inversion layer electrons holes using temperature body-bias-dependent Hall measurements on nitrided lateral MOSFETs. of transverse electric (Eeff) carrier...

It is well known that the circumferential waves supported by thin cylindrical, water-loaded shells correspond closely to those on a plate, i.e., Scholte–Stoneley wave A and Lamb A0,A1,A2,…, S0,S1,S2… . Until now, however, it had not been possible definitely observe acoustic excitation of A0 shell using steady-state or long-pulse incident sound (while S0 was clearly evident). The reason for this rapid decay propagating waves, whose high attenuation also rendered their multicircuit resonances...

We report a low-temperature aqueous solution growth of uniformly aligned ZnO nanorod arrays on flexible substrates. The substrate is Indium Tin Oxide (ITO) film coated polyethylene terephthalate (PET). Solutions with five different concentrations the precursors equimolar Zinc Nitrate and Hexamethylenetetramine (HMT) in distilled water were prepared to systematically study effect precursor concentration structural optical properties nanorods. It was concluded that have great influence...

We report on the photovoltaic characteristics of organic/inorganic hybrid solar cells fabricated 'flexible' transparent substrates. The cell device is composed ZnO nanorod array and bulk heterojunction structured organic layer which blend poly(3-hexylthiophene) (P3HT) (6,6)-phenyl C61 butyric acid methyl ester (PCBM). was grown indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates via a low-temperature (85 °C) aqueous solution process. consisting conjugated polymer P3HT...

A comparative study on the direct-current (dc) electrical performance and optical characteristics of unirradiated 120 MRad 60Co-gamma-ray (γ-ray) irradiated AlGaN/GaN high electron mobility transistors (HEMTs) was performed. The devices fabricated an HEMT epilayer structure show slight degradation/alteration in dc such as source–drain current–voltage (IDS-VDS), transfer (IDS-VGS), transconductance, gate current–voltage, indicating presence radiation-induced defects. Also, a shift flat band...

The correlation between phosphorus concentration in phospho-silicate glass (PSG) gate dielectrics and electrical properties of 4H-SiC MOS devices has been investigated. Varying P uptake PSG is achieved by changing the POCl3 post-oxidation annealing temperature. density interface traps (Dit) at PSG/4H-SiC decreases as amount interfacial increases. Most significantly, MOSFET channel mobility does not correlate with Dit for all samples, which highly unusual SiC MOSFETs. Further analysis reveals...

Hall measurements on NO annealed 4H-SiC MOS gated bars are reported in the temperature range 77 K- 423 K. The results indicate higher carrier concentration and lower trapping at increased temperatures, with a clear strong inversion regime all temperatures. In stark contrast to Si, mobility increases for K-373K, above which decreases slightly. maximum experimental was found be ~50 cm 2 V -1 s is only about 10% of bulk indicating that while annealing drastically improves trapping, it does not...