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.

High voltage (450 V) GaN Schottky rectifiers

Abstract: We fabricated high standoff voltage (450 V) Schottky rectifiers on hydride vapor phase epitaxy grown GaN on sapphire substrate. Several Schottky device geometries were investigated, including lateral geometry with rectangular and circular contacts, mesa devices, and Schottky metal field plate overlapping a SiO2 layer. The best devices were characterized by an ON-state voltage of 4.2 V at a current density of 100 A/cm2 and a saturation current density of 10^–5 A/cm2 at a reverse bias of 100 V. From the measured breakdown voltage we estimated the critical field for electric breakdown in GaN to be (2.2 ± 0.7) × 10^6 V/cm. This value for the critical field is a lower limit since most of the devices exhibited abrupt and premature breakdown associated with corner and edge effects.

Self-polarization effect in Pb(Zr,Ti)O3 thin films

Abstract: The self-polarization effect is investigated in Pb(Zr,Ti)O3 (PZT) thin films deposited by sol-gel and magnetron sputtering techniques. The effective piezoelectric coefficient of as-grown films, which is proportional to their initial polarization (self-polarization), is measured by a sensitive interferometric technique as a function of the annealing temperature, PZT composition, film thickness and bottom electrode material. The results indicate that the films are self-polarized by an internal bias field upon cooling through the phase transition temperature. It is suggested that a built-in field of a Schottky barrier between the PZT film and the bottom electrode is responsible for the observed effect. Self-polarization of the films is found to be very stable and in some cases to be as high as 90% of that produced by the subsequent room temperature poling. This property is very useful for piezoelectric and pyroelectric applications of PZT films since the poling procedure can be avoided. The properti...

GaN-on-Si Vertical Schottky and p-n Diodes

Abstract: This letter demonstrates GaN vertical Schottky and p-n diodes on Si substrates for the first time. With a total GaN drift layer of only 1.5- $\mu{\rm m}$ thick, a breakdown voltage (BV) of 205 V was achieved for GaN-on-Si Schottky diodes, and a soft BV higher than 300 V was achieved for GaN-on-Si p-n diodes with a peak electric field of 2.9 MV/cm in GaN. A trap-assisted space-charge-limited conduction mechanism determined the reverse leakage and breakdown mechanism for GaN-on-Si vertical p-n diodes. The on-resistance was 6 and 10 ${\rm m}\Omega\cdot{\rm cm}^{2}$ for the vertical Schottky and p-n diode, respectively. These results show the promising performance of GaN-on-Si vertical devices for future power applications.

Conductive and Stable Magnesium Oxide Electron‐Selective Contacts for Efficient Silicon Solar Cells

Abstract: A high Schottky barrier (>0.65 eV) for electrons is typically found on lightly doped n-type crystalline (c-Si) wafers for a variety of contact metals. This behavior is commonly attributed to the Fermi-level pinning effect and has hindered the development of n-type c-Si solar cells, while its p-type counterparts have been commercialized for several decades, typically utilizing aluminium alloys in full-area, and more recently, partial-area rear contact configurations. Here the authors demonstrate a highly conductive and thermally stable electrode composed of a magnesium oxide/aluminium (MgOx/Al) contact, achieving moderately low resistivity Ohmic contacts on lightly doped n-type c-Si. The electrode, functionalized with nanoscale MgOx films, significantly enhances the performance of n-type c-Si solar cells to a power conversion efficiency of 20%, advancing n-type c-Si solar cells with full-area dopant-free rear contacts to a point of competitiveness with the standard p-type architecture. The low thermal budget of the cathode formation, its dopant-free nature, and the simplicity of the device structure enabled by the MgOx/Al contact open up new possibilities in designing and fabricating low-cost optoelectronic devices, including solar cells, thin film transistors, or light emitting diodes.

Single‐crystal‐aluminum Schottky‐barrier diodes prepared by molecular‐beam epitaxy (MBE) on GaAs

Abstract: Metal‐semiconductor surface barriers were formed by epitaxially grown Al(001) on GaAs(001) with MBE at room temperature. The diodes exhibit nearly ideal electrical characteristics. It is also demonstrated that different barrier heights may be achieved by growing Al layers on MBE GaAs surfaces with different surface stoichiometries.