Photoluminescence and Photocurrent from InGaN/GaN Diodes with Quantum Wells of Different Widths and Polarities.

We compare the optical properties of four diode samples differing by built-in field direction and width of the InGaN quantum well in the active layer: two diodes with standard layer sequences and 2.6 and 15 nm well widths and two diodes with inverted layer ordering (due to the tunnel junction grown before the structure) also with 2.6 and 15 nm widths.

Bidirectional light-emitting diode as a visible light source driven by alternating current.

Gallium nitride-based light-emitting diodes have revolutionized the lighting market by becoming the most energy-efficient light sources. However, the power grid, in example electricity delivery system, is built based on alternating current, which raises problems for directly driving light emitting diodes that require direct current to operate effectively. In this paper, we demonstrate a proof-of-concept device that addresses this fundamental issue - a gallium nitride-based bidirectional light-emitting diode.

Ion implantation of tunnel junction as a method for defining the aperture of III-nitride-based micro-light-emitting diodes.

We report on III-nitride-based micro-light-emitting diodes (µLEDs) operating at 450 nm wavelength with diameters down to 2 µm. Devices with a standard LED structure followed by a tunnel junction were grown by plasma-assisted molecular beam epitaxy. The emission size of µLEDs was defined by shallow He implantation of the tunnel junction region.

Electrically pumped blue laser diodes with nanoporous bottom cladding.

We demonstrate electrically pumped III-nitride edge-emitting laser diodes (LDs) with nanoporous bottom cladding grown by plasma-assisted molecular beam epitaxy on c-plane (0001) GaN. After the epitaxy of the LD structure, highly doped 350 nm thick GaN:Si cladding layer with Si concentration of 6·10 cm was electrochemically etched to obtain porosity of 15 ± 3% with pore size of 20 ± 9 nm. The devices with nanoporous bottom cladding are compared to the reference structures.

Dependence of InGaN Quantum Well Thickness on the Nature of Optical Transitions in LEDs.

The design of the active region is one of the most crucial problems to address in light emitting devices (LEDs) based on III-nitride, due to the spatial separation of carriers by the built-in polarization. Here, we studied radiative transitions in InGaN-based LEDs with various quantum well (QW) thicknesses-2.6, 6.

Distributed-feedback blue laser diode utilizing a tunnel junction grown by plasma-assisted molecular beam epitaxy.

In this paper, we demonstrate a novel approach utilizing tunnel junction (TJ) to realize GaN-based distributed feedback (DFB) laser diodes (LDs). Thanks to the use of the TJ the top metal contact is moved to the side of the ridge and the DFB grating is placed directly on top of the ridge. The high refractive index contrast between air and GaN, together with the high overlap of optical mode with the grating, provides a high coupling coefficient.

Stack of two III-nitride laser diodes interconnected by a tunnel junction.

We demonstrate a stack of two III-nitride laser diodes (LDs) interconnected by a tunnel junction grown by plasma-assisted molecular beam epitaxy. Hydrogen-free growth is used to obtain as-grown p-type conductivity essential for buried tunnel junctions (TJ). We show the impact of the design of tunnel junction.