An AlGaN/GaN High Electron Mobility Transistor With a Built-In Light Emitter Using Radiative Recombination of Two-Dimensional Electron Gas and Holes

Abstract

This paper reports a novel HEMT structure that includes a built-in light emitter through band-to-band radiative recombination that is provided via holes from the p-GaN layer and electrons from the 2DEG. The electrical switching and illumination functions are able to be combined into a single device. The peak of the emitted light spectrum is located at 365 nm, corresponding to the bandgap of the GaN layer. This device uses a simple and cost-effective process, and shows the possibility for use in applications such as optical interconnects and optoelectronic integrated circuits. INDEX TERMS GaN, HEMT, light emitting devices, two-dimensional electron gas.

Design and Simulation of Normally Off High‐Electron‐Mobility Light‐Emitting Transistor

“…The V th was estimated to be 0.2 V. Figure 1b shows the output characteristics ( I D – V DS ) with applied gate voltages ranging from 0 to 3 V. The saturated drain current reached its maximum value of 520 mA mm −1 with an on resistance of 3.84 Ω mm; the differential resistance is calculated from . [ 16 ] At higher applied voltages, the high electric field would produce self‐heating and hot electron degradation effects, which accelerate phonon scattering and reduce carrier mobility, thus reducing the drain current. [ 17 ]…”

“…LET Figure 3 depicts the electrical characteristics of the proposed LET at V DS ¼ 8 V; the threshold voltage was estimated to be 0.2 V, the same as the HEMT, with a slight increase in current due to conductivity modulation from hole injection. [16] The output characteristics (I D -V DS ) with gate voltages ranging from 0 to 3 V are shown in Figure 3b. The built-in voltage between the p-GaN and 2DEG channel layers in the drain region resulted in a voltage offset of approximately 3.2 V, which agrees with other reported values.…”

Study on the Effects of Quantum Well Location on Optical Characteristics of AlGaN/GaN Light-Emitting HEMT

“…In order to simplify the processes, and reduce the cost and the parasitic effects from the metal interconnection, an AlGaN/GaN HEMT structure is demonstrated in our previous works that includes a built-in light emitter, named a light-emitting HEMT(LE-HEMT). Different from typical LEDs, an LE-HEMT uses radiative recombination of holes from p-GaN and electrons from 2DEG to generate light [ 7 ]. In order to improve efficiency and light intensity, a single quantum well was inserted for better electron and hole confinement [ 8 ].…”