Impact of p-AlGaN/GaN hole injection layer on GaN-based vertical cavity surface emitting laser diodes [Invited]

Abstract

The hole injection capability is essentially important for GaN-based vertical cavity surface emitting lasers (VCSELs) to enhance the laser power. In this work, we propose GaN-based VCSELs with the p-AlGaN/p-GaN structure as the p-type hole supplier to facilitate the hole injection. The p-AlGaN/p-GaN heterojunction is able to store the electric field and thus can moderately adjust the drift velocity and the kinetic energy for holes, which can improve the thermionic emission process for holes to travel across the p-type electron blocking layer (p-EBL). Besides, the valence band barrier height in the p-EBL can be reduced as a result of usage of the p-AlGaN layer. Therefore, the better stimulated radiative recombination rate and the increased laser power are obtained, thus enhancing the 3 dB frequency bandwidth. Moreover, we also investigate the impact of the p-AlGaN/p-GaN structure with various AlN compositions in the p-AlGaN layer on the hole injection capability, the laser power, and the 3 dB frequency bandwidth.

Study of Ga-Polar and N-Polar GaN-Based Green VCSELs by Simulation

“…The offset ratio of conduction/valence band in the MQWs was set to be 70:30. To account for optical losses, the average optical background loss of the n-GaN, MQWs, EBL, and p-GaN layers in the cavity was set to 1000 m -1 [26]. Figure 2(a) shows the power-current (P-I) characterization of experimental VCSEL (red dot) and simulated VCSEL (black line).…”

Simulation of performance enhancement of GaN-based VCSELs by composition gradient InGaN last-quantum barrier

“…Crosslight PICS3D was used to simulate the optical and electrical properties of VCSELs, which contain current continuity equations, drift-diffusion equations, Schrödinger and Poisson's equations, etc [18]. The Auger recombination coefficient was set to be 1.4 × 10 −31 cm 6 s −1 to account for Auger recombination in the material, while the Shockley-Read-Hall (SRH) lifetime is 1 × 10 −8 s, which consist with the previous results [19][20][21][22][23].…”

“…The polarization level was set as 40% to approximate the polarized charge at the interface. The conduction/valence band offset ratio was set to be 70:30 for MQWs and 50:50 for AlGaN/GaN interface [18,24]. The average optical background loss of the n-GaN, MQWs, EBL, and p-GaN layers in the cavity was set to 1000 m −1 [22,25].…”

Optical and electrical properties of Sb-doped β-Ga2O3 crystals grown by OFZ method

“…In recent years, the β-Ga 2 O 3 single crystal has attracted great interest in research due to its excellent optical and electrical properties [1][2][3] . Properties of the β-Ga 2 O 3 single crystal such as its huge bandgap (4.8 eV) [4] , high-breakdown electric field (8 MV/cm) [5] , and short absorption edge [6] make them appropriate materials for deep ultraviolet (UV) electronic devices and high power, high voltage, and low loss power devices [7][8][9][10][11][12][13] . In particular, β-Ga 2 O 3 single crystals can be obtained by the melt method, which includes the edge-defined film-fed growth [14] , optical floating zone (OFZ) [15] , Czochralski [16] , and vertical Bridgman [17] methods.…”