Schottky barrier

About: Schottky barrier is a research topic. Over the lifetime, 22570 publications have been published within this topic receiving 427746 citations. The topic is also known as: Schottky barrier junction.

Electron diffusion length and lifetime in p-type GaN

Abstract: We report on electron beam induced current and current–voltage (I–V) measurements on Schottky diodes on p-type doped GaN layers grown by metal organic chemical vapor deposition. A Schottky barrier height of 0.9 eV was measured for the Ti/Au Schottky contact from the I–V data. A minority carrier diffusion length for electrons of (0.2 ± 0.05) µm was measured for the first time in GaN. This diffusion length corresponds to an electron lifetime of approximately 0.1 ns. We attempted to correlate the measured electron diffusion length and lifetime with several possible recombination mechanisms in GaN and establish connection with electronic and structural properties of GaN.

Al on GaAs(110) interface: Possibility of adatom cluster formation

Abstract: A reexamination of the experimental data and previous electronic-structure calculations on the prototype Schottky system Al/GaAs(110), together with new calculations, indicates that at low coverages and temperatures neither a covalent bond nor a metallic bond is likely to be formed between Al and the substrate. Instead, the predominant species is likely to be Al clusters which interact only weakly and largely nondirectionally with the substrate. In contrast with all previous theoretical models which assume an epitaxially ordered array of chemisorption bonds even at submonolayer coverage, it then appears that the formation of a Schottky barrier as well as other physical and chemical characteristics of the interface (e.g., core level and exciton shifts, valence-band photoemission spectra, gap states, surface atomic relaxation) are not explainable in terms of strong and ordered chemisorption bonds. This weakly interacting cluster model leads to several interesting predictions regarding the atomic structure and spectroscopy of this metal-semiconductor interface at the initial stages of its formation. The properties of the interface at higher temperatures (i.e., after annealing) are discussed in terms of an Al-Ga exchange reaction.

Analysis of degradation mechanisms in lattice-matched InAlN/GaN high-electron-mobility transistors

Abstract: We address degradation aspects of lattice-matched unpassivated InAlN/GaN high-electron-mobility transistors (HEMTs). Stress conditions include an off-state stress, a semi-on stress (with a partially opened channel), and a negative gate bias stress (with source and drain contacts grounded). Degradation is analyzed by measuring the drain current, a threshold voltage, a Schottky contact barrier height, a gate leakage and an ideality factor, an access, and an intrinsic channel resistance, respectively. For the drain-gate bias < 38 V parameters are only reversibly degraded due to charging of the pre-existing surface states. This is in a clear contrast to reported AlGaN/GaN HEMTs where an irreversible damage and a lattice relaxation have been found for similar conditions. For drain-gate biases over 38 V InAlN/GaN HEMTs show again only temporal changes for the negative gate bias stresses; however, irreversible damage was found for the off-state and for the semi-on stresses. Most severe changes, an increase in the intrinsic channel resistance by one order of magnitude and a decrease in the drain current by similar to 70%, are found after the off-state similar to 50 V drain-gate bias stresses. We conclude that in the off-state condition hot electrons may create defects or ionize deep states in the GaN buffer or at the InAlN/GaN interface. If an InAlN/GaN HEMT channel is opened during the stress, lack of the strain in the barrier layer is beneficial for enhancing the device stability.

High-performance single CdS nanowire (nanobelt) Schottky junction solar cells with Au/graphene Schottky electrodes.

Abstract: High-performance single CdS nanowire (NW) as well as nanobelt (NB) Schottky junction solar cells were fabricated. Au (5 nm)/graphene combined layers were used as the Schottky contact electrodes to the NWs (NBs). Typical as-fabricated NW solar cell shows excellent photovoltaic behavior with an open circuit voltage of ∼0.15 V, a short circuit current of ∼275.0 pA, and an energy conversion efficiency of up to ∼1.65%. The physical mechanism of the combined Schottky electrode was discussed. We attribute the prominent capability of the devices to the high-performance Schottky combined electrode, which has the merits of low series resistance, high transparency, and good Schottky contact to the CdS NW (NB). Besides, a promising site-controllable patterned graphene transfer method, which has the advantages of economizing graphene material and free from additional etching process, was demonstrated in this work. Our results suggest that semiconductor NWs (NBs) are promising materials for novel solar cells, which hav...

On temperature-dependent experimental I-V and C-V data of Ni/n-GaN Schottky contacts

Abstract: We report the current-voltage (I-V) and capacitance-voltage characteristics (C-V) of Ni/n-GaN Schottky diodes Gallium nitride is a highly promising wide band gap semiconductor for applications in high power electronic and optoelectronic devices which require Schottky barriers for modulating the channel mobile charge The I-V and C-V characteristics of the diodes have been measured in the temperature range of 80–400 K with steps of 20 K Thermal carrier concentration and barrier height versus temperature plots have been obtained from the C−2-V characteristics, and a value of α=−140 meV/K for temperature coefficient of the barrier height The modified activation energy plot according to the barrier inhomogeneity model has given the Richardson constant A∗ as 80 or 85 A/(cm2 K2)