Nano-photodiodes with a subwavelength active area using the optical near-field enhanced by surface plasmon resonance are proposed. We fabricated a Si Schottky photodiode that consists of an active area of 300 nm in diameter and a surface plasmon antenna to generate the carrier within the active area efficiently. The fabricated photodiode shows an increase of the photocurrent by several tenfold compared to that without a surface plasmon antenna. This result suggests an enhanced photogeneration of carriers in a semiconductor via surface plasmon resonance. Such a Si nano-photodiode is a potential high-speed optical signal detector because the opto-electronic conversion process occurs within a subwavelength scale.

GaAs-GaAsP and InGaAs-AlGaAs strained-layer superlattice photocathodes are presented as emission sources for highly polarized electron beams. The GaAs-GaAsP cathode achieved a maximum polarization of 92(±6)% with a quantum efficiency of 0.5%, while the InGaAs-AlGaAs cathode provides a higher quantum efficiency (0.7%) but a lower polarization (77(±5)%). Criteria for achieving high polarization using superlattice (SL) photocathodes are discussed based on experimental spin-resolved quantum efficiency spectra.

Articles you may be interested inA detailed coupled-mode-space non-equilibrium Green's function simulation study of source-to-drain tunnelling in gate-all-around Si nanowire metal oxide semiconductor field effect transistors Model of random telegraph noise in gate-induced drain leakage current of high-k gate dielectric metal-oxidesemiconductor field-effect transistors Appl. Phys. Lett. 100, 033501 (2012); 10.1063/1.3678023 Analytical approach to integrate the different components of direct tunneling current through ultrathin gate oxides in n-channel metal-oxide-semiconductor field-effect transistors J. Appl. Phys. 93, 1064 (2003); 10.1063/1.1527710 On-off switching of edge direct tunneling currents in metal-oxide-semiconductor field-effect transistors Appl. Phys. Lett. 81, 3488 (2002); 10.1063/1.1518563Fabrication of 30 nm gate length electrically variable shallow-junction metal-oxide-semiconductor field-effect transistors using a calixarene resist

A new three-terminal tunnel device, the surface tunnel transistor (STT), is proposed and its operation is demonstrated using GaAs/AlGaAs. STT consists of n+/i/p+ diode structure with an insulated gate in the i-region, which is similar to a MOSFET. However, the source and drain are oppositely doped. The most important feature of this device is that the drain must be so highly degenerated that a tunnel junction is formed with a two-dimensional (2D) electron channel under the gate. The tunneling current from source to drain is controlled by the gate bias through the concentration of accumulated 2D electrons under the gate. GaAs STTs with i-Al0.6Ga0.4As as a gate insulator are fabricated using MBE regrowth techniques on a mesa structure. This device exhibits transistor characteristics at 77 K and at room temperature, which confirms the new operation principle of STTs.

A strong right-left scattering asymmetry has been observed in resonant electron capture for H i molecular ions impinging on Na(3p) oriented states excited by circularly polarized laser light at keV collision energies. The collision velocity v, is close to one third of the orbital velocity of the sodium 3p electron. The measured asymmetry is comparable to the orientation effect observed in quasi-resonant charge transfer for protons colliding with Na(3p) oriented targets.