We report on the fabrication and photovoltaic characteristics of InGaN solar cells by exploiting InGaN/GaN multiple quantum wells MQWs with In contents exceeding 0.3, attempting to alleviate to a certain degree the phase separation issue and demonstrate solar cell operation at wavelengths longer than previous attainments 420 nm . The fabricated solar cells based on In0.3Ga0.7N /GaN MQWs exhibit...

Strong photoluminescence and radiative recombination lifetimes longer than 1 ns at room temperature have been observed in GaN/Si/InGaN/GaN structures containing InGaN submicron islands. The flat islands, with a width at their base in the order of 200 nm and a height in the order of 1—2 nm, grow in a spiral mode around dislocations with partial or pure screw character after a passivation of the ...

We demonstrate the strong influence of strain on the morphology and In content of InGaN insertions in GaN nanowires, in agreement with theoretical predictions which establish that InGaN island nucleation on GaN nanowires may be energetically favorable, depending on In content and nanowire diameter. EDX analyses reveal In inhomogeneities between the successive dots but also along the growth dire...

The epitaxial growth of zinc-blende (cubic) GaN and InGaN on GaAs with a common cleavage plane and readily high-quality, low-cost wafers may be considered as an alternative approach for the future realization of cleaved laser cavities. To obtain detailed information about the potential of cubic GaN and InGaN for device applications we performed optical gain spectroscopy accompanied by time-inte...

The V-pits and potential fluctuations in InGaN/GaN multiple quantum wells (MQWs) are key factors for understanding the performance of InGaN/GaN-based light-emitting diodes (LEDs). However, photoluminescence (PL) measurements using conventional optical microscopy only provide ensemble information due to the spatial resolution limit, known as the diffraction barrier, which hinders the analysis of...

Spatially resolved photoluminescence PL of InGaN/GaN/AlGaN-based quantum-well-structured light-emitting diodes LEDs with a yellow-green light 530 nm and an amber light 600 nm was measured by using confocal microscopy. Submicron-scale spatial inhomogeneities of both PL intensities and spectra were found in confocal micro-PL images. We also found clear correlations between PL intensities and peak...

0026-2714/$ see front matter 2012 Elsevier Ltd. A http://dx.doi.org/10.1016/j.microrel.2012.06.051 ⇑ Corresponding author. Tel.: +7 812 247 91 93; fax E-mail address: [email protected] (E.I. Shabunina). Unpredictable fast failure of blue power InGaN/GaN LEDs is caused by redistribution of In under action of injection currents between nano-scale regions of InGaN alloy with non-equilibrium composi...

We have made substantial progress in the development of GaN photocathodes, including crystalline and polycrystalline GaN and InGaN coatings grown by chemical vapor deposition or molecular beam epitaxy on sapphire substrates. GaN and InGaN photocathodes have been developed with efficiencies up to 70% and cutoffs at 380 nm with low out of band response, and high stability and longevity. Samples h...

We demonstrate that the efficiency droop phenomenon in multiple quantum well InGaN/GaN light-emitting diodes (LEDs) may be connected to the current crowding effect. A numerical model of internal quantum efficiency calculation is presented that takes into account nonuniform lateral carrier injection in the active region. Based on this model, we examine the effect of current crowding on the effic...

We report on the growth and exploitation of InGaN epilayers as a photoelectrochemical cell PEC material for direct generation of hydrogen by splitting water using photoelectrochemical hydrolysis. Under white light illumination, a drastic dependence of the photocurrent density on the In content was observed. Direct hydrogen gas generation by splitting water was accomplished using an n-type InxGa...