Room-temperature continuous-wave electrically pumped InGaN/GaN quantum well blue laser diode directly grown on Si

Abstract

Current laser-based display and lighting applications are invariably using blue laser diodes (LDs) grown on free-standing GaN substrates, which are costly and smaller in size compared with other substrate materials.1–3 Utilizing less expensive and large-diameter Si substrates for hetero-epitaxial growth of indium gallium nitride/gallium nitride (InGaN/GaN) multiple quantum well (MQW) structure can substantially reduce the cost of blue LDs and boost their applications. To obtain a high crystalline quality crack-free GaN thin film on Si for the subsequent growth of a blue laser structure, a hand-shaking structure was formed by inserting Al-composition step down-graded AlN/AlxGa1−xN buffer layers between GaN and Si substrate. Thermal degradation in InGaN/GaN blue MQWs was successfully suppressed with indium-rich clusters eliminated by introducing hydrogen during the growth of GaN quantum barriers (QBs) and lowering the growth temperature for the p-type AlGaN/GaN superlattice optical cladding layer. A continuous-wave (CW) electrically pumped InGaN/GaN quantum well (QW) blue (450 nm) LD grown on Si was successfully demonstrated at room temperature (RT) with a threshold current density of 7.8 kA/cm2.

Hybrid quadrupole plasmon induced spectrally pure ultraviolet emission from a single AgNPs@ZnO:Ga microwire based heterojunction diode

“…Due to its outstanding piezoelectric characteristics, excellent electronic transport and optical features, superior optical gain behavior, biocompatibility, chemical stability and so on, ZnO (wide bandgap of 3.37 eV, and large exciton binding energy of 60 meV) has been widely used in versatile applications, for instance high-efficiency photonic devices and short-wavelength optoelectronic devices (e.g., ultraviolet light-emitting diodes, laser diodes, and ultraviolet-blind photodetectors). [1][2][3][4][5] Within the comprehensive investigations of ZnO, there is increasing interest in nano/microstructures, which have already demonstrated their incomparable utility as eld effect transistors, optically and electrically pumped lasers, photodetectors, batteries, and chemical and biological sensors. [6][7][8] For the past few years, great efforts have also been devoted to preparing lowdimensional ZnO nano/microstructures, such as by metalorganic chemical vapor deposition, thermal evaporation, chemical vapor transport, laser ablation, and so on.…”

Elimination of the internal electrostatic field in two-dimensional GaN-based semiconductors

“…GaN-based semiconductors are highlighted for their excellent properties, such as tunable and direct band gap, high thermal conductivity, and good chemical stability 1 . The materials and devices have been extensively investigated in recent decades, which has led to significant progress in light-emitting diodes [2][3][4][5][6] , photodetectors [7][8][9] , and laser diodes [10][11][12] . However, the great success in lighting devices is mainly limited by the polar material growth along the c-axis [0001].…”

InGaN-diode-pumped AlGaInP VECSEL with sub-kHz linewidth at 689 nm

“…related to the use of sapphire substrates that have lower thermal conductivity (≈ 24 Wm −1 K −1 ) when compared to GaAs substrates (≈ 46 Wm −1 K −1 ) at room temperature [40][41][42]. Other substrates such as GaN and Si [43] are being investigated to improve the thermal performance of the diode but no device is yet commercially available. There is therefore a high impedance in the path of the heat towards the heatsink during laser operation.…”