The benefits of utilizing transparent conductive oxide on top of a thin p-GaN layer for continuous-wave (CW) operation of blue laser diodes (LDs) were investigated. A very low operating voltage of 5.35 V at 10 kA/cm was obtained for LDs with 250 nm thick p-GaN compared to 7.3 V for LDs with conventional 650 nm thick p-GaN. An improved thermal performance was also observed for the thin p-GaN samples resulting in a 40% increase in peak light output power and a 32% decrease in surface temperature. Finally, a tradeoff was demonstrated between low operating voltage and increased optical modal loss in the indium tin oxide (ITO) with thinner p-GaN. LDs lasing at 445 nm with 150 nm thick p-GaN had an excess modal loss while LDs with an optimal 250 nm thick p-GaN resulted in optical output power of 1.1 W per facet without facet coatings and a wall-plug efficiency of 15%.

No abstract

Thin epitaxial layers of NiInGaAs formed by solid state reaction of Ni on (100) In0.53Ga0.47As are used as metal source and drain regions for In0.53Ga0.47As metal oxide field effect transistors. Here, the authors present a structural and chemical analysis of this phase. The stoichiometry of the layer was determined as Ni2In0.53Ga0.47As. Transmission electron microscopy revealed an abrupt interface and a detailed x-ray diffraction analysis showed that the layer is of a hexagonal lattice, which grows epitaxially with the orientation relations of {100}InGaAs||{100}NiInGaAs; ⟨011¯⟩InGaAs||[001]NiInGaAs. Only one domain can be observed in this epitaxial growth. Understanding the structure of these layers is a crucial step not only in their incorporation into InGaAs based devices but also a step toward novel devices.

We obtained InGaN laser diodes (LDs) with a low optical loss (1.9 ± 0.6 cm −1 ) by utilizing an undoped In 0.07 Ga 0.93 N p-waveguide (p-WG) and a remote p-AlGaN electron blocking layer. This improvement, however, was accompanied by a low injection efficiency (37%) and a poor material gain. Electroluminescence measurements and energy band diagram simulations revealed excessive carrier accumulation in the p-WG region, which was suppressed by introducing an undoped indium-free GaN p-WG. This enabled LDs with a high material gain, a low optical loss (4.6 ± 0.7 cm −1 ), an improved injection efficiency (60%), and a peak light output power of 1.6 W at 1.5 A.

Articles you may be interested inVery low resistance alloyed Ni-based ohmic contacts to InP-capped and uncapped n+-In0.53 Ga0.47As