Double heterojunction lasers and quantum well lasers

Liu

ACS Appl. Mater. Interfaces

et al. 2016

Two-dimensional (2D) atomic-layered semiconductors are important for nextgeneration electronics and optoelectronics. Here, we designed the growth of an MoSe 2 atomic layer on a lattice-matched GaN semiconductor substrate. The results demonstrated that the MoSe 2 films were less than three atomic layers thick and were single crystalline of MoSe 2 over the entire GaN substrate. The ultrathin MoSe 2 /GaN heterojunction diode demonstrated ∼850 nm light emission and could also be used in photovoltaic applications.

Section: ■ Introductionmentioning

confidence: 99%

Wafer-Size and Single-Crystal MoSe₂ Atomically Thin Films Grown on GaN Substrate for Light Emission and Harvesting

Liu

ACS Appl. Mater. Interfaces

et al. 2016

Applied Physics Letters

Threshold current of single quantum well lasers: The role of the confining layers

Nagle¹,

Hersee²,

Krakowski³

et al. 1986

The threshold current density of single quantum well (SQW) GaAs/GaAlAs lasers is calculated, taking into account the carrier populations of the confining layer. We find that these populations are significant when compared to those of the quantum well. This effect explains the better performance of the graded-index separate confinement SQW laser when compared to the separate confinement heterostructure laser, as well as the T0 performance of such lasers.

Trapping of carriers in single quantum wells with different configurations of the confinement layers

et al. 1988

This paper reports detailed experimental studies of low-temperature carrier trapping in GaAs/A1"Gal "As single quantum wells with 5 nm and 1.2 nm thickness, respectively, with different confinement structures. Trapping efficiency and trapping dynamics are studied by means of photoluminescence, photoluminescence excitation spectroscopy, and picosecond luminescence spectroscopy. %'e obtain trapping efficiencies of about 40% for both the single quantum wells without additional confinement and separate-confinement-heterostructure quantum wells. The percentage of trapped carriers increases to about 60%%uo to 80% for quantum wells cladded by gradedindex separate-confinement heterostructures with parabolic band-gap profile. The maximum trapping eSciency of about 100% has been observed for a separate-confinement heterostructure with a linear band-gap profile. Interlayer well width fluctuations are found to be unimportant for the trapping behavior in our samples. Trapping times are appreciably shorter than the rise times of the quantum well photoluminescence, which are between 60 and 100 ps for the different structures.Surface recombination in the 0.2-p, m-thick Al"Gal "As cladding layer does not reduce the trapping efficiency of the single quantum well without additional confinement compared with the separateconfinement heterostructure. An effective trapping area with about 80 nm width can be deduced on the basis of these results for the quantum-well structures with ungraded cladding layers.