Near-UV electroluminescence in unipolar-doped, bipolar-tunneling GaN/AlN heterostructures

Abstract

Cross-gap light emission is reported in n-type unipolar GaN/AlN double-barrier heterostructure diodes at room temperature. Three different designs were grown on semi-insulating bulk GaN substrates using molecular beam epitaxy (MBE). All samples displayed a single electroluminescent spectral peak at 360 nm with full-width at half-maximum (FWHM) values no greater than 16 nm and an external quantum efficiency (EQE) of ≈0.0074% at 18.8 mA. In contrast to traditional GaN light emitters, p-type doping and p-contacts are completely avoided, and instead, holes are created in the GaN on the emitter side of the tunneling structure by direct interband (that is, Zener) tunneling from the valence band to the conduction band on the collector side. The Zener tunneling is enhanced by the high electric fields (~5 × 106 V cm−1) created by the notably large polarization-induced sheet charge at the interfaces between the AlN and GaN.

Epitaxial Growth and Characterization of AlInN-Based Core-Shell Nanowire Light Emitting Diodes Operating in the Ultraviolet Spectrum

“…The AlInN LEDs have excellent current-voltage characteristic with low resistance measured at room temperature, shown in Figure 4(a). The leakage current was found to be very small which is about 1 µA at -8 V. Turn on voltage of these UV nanowire LEDs is ~ 5 V which is significantly lower compared to current thin-film AlGaN LEDs at similar wavelength range 44,45 and is also better/comparable to that of currently reported AlGaN UV nanowire LEDs 43,46,47 . Figure 4 This observation agrees well with the simulation results in which the TM polarized emission is more than two orders of magnitude strong than TE polarized light, shown in Figure 5(b).…”

Repeatable Room Temperature Negative Differential Resistance in AlN/GaN Resonant Tunneling Diodes Grown on Sapphire

“…[36][37][38][39][40] Here, in AlN/GaN double barrier structures, the polarization fields lead to an inartificial asymmetric RTD structure, where the second barrier is much thicker than the first as shown in Figure 3a. [36][37][38][39][40] Here, in AlN/GaN double barrier structures, the polarization fields lead to an inartificial asymmetric RTD structure, where the second barrier is much thicker than the first as shown in Figure 3a.…”

“…Giant polarization fields in wurtzite III‐nitride semiconductors have already encouraged many innovative findings and applications in device physics . Here, in AlN/GaN double barrier structures, the polarization fields lead to an inartificial asymmetric RTD structure, where the second barrier is much thicker than the first as shown in Figure a.…”

In situ fabrication of Al surface plasmon nanoparticles by metal–organic chemical vapor deposition for enhanced performance of AlGaN deep ultraviolet detectors

“…AlN and AlGaN-based materials are typical representatives of third-generation semiconductor materials with direct transition energy bands and wide band gap, as well as excellent thermal and chemical stability, which are extensively applied to highperformance ultraviolet (UV) and deep-ultraviolet (DUV) photoelectric devices, such as photodetectors (PDs), light emitting diodes (LEDs) and laser diodes (LDs). [1][2][3][4][5][6] Among them, AlGaN-based UV emitters and detectors show potential application in biomedical, sterilization, ame detection and missile warning, 7,8 and they have received extensive attention. Different types of AlGaN-based UV photodetectors with promising performance have been demonstrated, such as Schottky type, metal-semiconductor-metal (MSM) type, p-n/p-i-n type and avalanche detectors.…”