Wide bandgap over 3 eV and high p-doping BeZnTe grown on InP substrates by molecular beam epitaxy

Physica Status Solidi (b)

Nakai

Hayami

et al. 2006

Self Cite

Aging characteristics of BeZnSeTe yellow light emitting diodes (LEDs) fabricated on InP substrates by molecular beam epitaxy were investigated under direct current injections at room temperature. It was shown that the decay speed of the light output during the aging was slower than that of conventional ZnCdSe/MgZnSSe LEDs. A long lifetime more than 5000 h and a half lifetime of 5180 h were obtained at a current density of 130 A/cm 2 . The half lifetimes of the BeZnSeTe LEDs were about three orders of magnitude greater than that of the ZnCdSe/MgZnSSe LEDs. These results proved high reliability of the BeZnSeTe LED. Investigating the aging characteristics of the applied voltage, the injection current, and the emission spectra showed that the output decay was caused by degradation of the active layer of the LEDs.

Section: Introductionmentioning

confidence: 99%

“…High n-type doping of MgZnCdSe is currently obtained using chlorine as a dopant. BeZnTe lattice-matched to InP has a wide bandgap of about 2.8 eV and is superior in p-type doping [2]. These features suggest that basic laser diode (LD) and light emitting diode (LED) structures can be constructed using MgZnCdSe and BeZnTe materials.…”

Section: Introductionmentioning

confidence: 99%

Long life operations over 5000 hours of BeZnSeTe/MgZnCdSe visible light emitting diodes on InP substrates

Physica Status Solidi (b)

Nakai

Hayami

et al. 2006

Self Cite

“…By the introduction of beryllium chalcogenides into II-VI laser diodes (LDs), it is expected that the defect generation and propagation are suppressed and thus the device lifetime is lengthened. In this study, we have investigated novel BeZnTe II-VI alloys [29,30] and related superlattices [32][33][34][35] which could be lattice-matched to InP substrates. BeZnTe lattice-matched to InP can serve as candidates for pcladding layers of II-VI LDs and LEDs on InP substrates [29,30] because of its wide bandgap (see Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, we have proposed novel ZnCdSe/BeZnTe and MgSe/BeZnTe superlattices to solve the problems. In this study, We synthesized BeZnTe ternaries [29,30], ZnCdSe/BeZnTe [32][33][34] and MgSe/BeZnTe superlattices [34][35][36], for the first time. These materials were utilized to fabricate LEDs emitting in the wide visible range from 554 to 644 nm [33,35], and long lifetime LED operation over 3500 hours was demonstrated [39].…”

Section: Introductionmentioning

confidence: 99%

Yellow‐green emitters based on beryllium‐chalcogenides on InP substrates

Kishino

2004

phys. stat. sol. (c)

Self Cite

PACS 78.20.Ci, 78.55.Et, 78.66.Hf, 81.05.Dz, 81.15.Hi, 85.60.Jb II-VI compound materials containing beryllium-chalcogenides such as BeZnTe, ZnCdSe/BeZnTe, and MgSe/BeZnTe superlattices grown on InP substrates have been investigated for yellow-green emitters employing molecular beam epitaxy. Photoluminescence peaks of ZnCdSe/BeZnTe superlattices were widely controlled from 740 to 507 nm by changing the layer thickness combination. Applying ZnCdSe/BeZnTe and MgSe/BeZnTe superlattices, visible light emitting diodes (LEDs) were fabricated emitting at the wavelengths from 554 (yellow-green) to 644 nm (red) at room temperature. For yellow (575nm) LEDs, a long lifetime more than 3500 hours was demonstrated. Laser diodes consisting of a ZnCdSe active, a MgSe/ZnCdSe superlattice n-cladding, and a MgSe/BeZnTe superlattice p-cladding layers successfully operated with yellow-green lasing emissions around 560 nm at 77 K.

“…This failure is due to the lack of suitable p-cladding materials for LDs. We have proposed a BeZnTe ternary alloy [8] and related materials [9, 10] as a new p-cladding layer and visible LEDs and LDs were successfully fabricated.In this paper, we describe LED and LD structures based on the II-VI materials grown on InP, as well as what structures might be suitable for visible LED and LD with these materials. We then explain our experimental results of the ZnCdSe single quantum well (SQW) LDs.…”

mentioning

confidence: 99%

Development of yellow‐green LEDs and LDs using MgZnCdSe‐BeZnTe superlattices on InP substrates by MBE

Che

Physica Status Solidi (b)

Kikuchi

et al. 2004

Self Cite

PACS 42.55.Px, 73.40.Lq, 85.60.Jb We have fabricated yellow-green light emitting diodes (LEDs) and laser diodes (LDs) by using II-VI compounds grown on an InP substrate. A separate confinement hetero-structure was fabricated by means of Cl-doped MgSe/ZnCdSe SuperLattices(SLs) for n-side layers, a ZnCdSe Single Quantum Well (SQW) for an active region, and N-doped MgSe/BeZnTe SLs for p-side layers. Lasing emission around 560 nm could be observed at a current density over 2.5 kA/cm 2 under the pulsed current injection at 77 K. In order to obtain a lasing operation at room temperature, it is necessary to decrease the resistance of the LD and to suppress the current leakage at the interface between the active region and the p-side region.1 Introduction II-VI compound semiconductors are very attractive as materials for visible light emittors, since their bandgap energies can cover the whole visible light range. Various semiconductor laser materials and structures have been proposed to date. Among them, only II-VI LDs can operate in the yellow-green wavelength region. In the case of MgZnSSe based LDs grown on GaAs substrates, a lasing emission was observed in a blue-green light region around 500 nm under the continuous wave operation at room temperature (RT) [1]. Moreover, recently ZnCdSSe and CdSe quantum dots based LDs have also been proposed [2,3], of which lasing wavelengths were from 500 nm to 560 nm at RT. Although these LDs grown on GaAs show relatively good performances, degradation still remains as a serious problem. We have proposed II-VI compounds on InP substrates instead of ones grown on GaAs in order to overcome the device degradation problem. Because the II-VI material system on InP does not have any strain in the active layer, the device structure can be designed under lattice matching to InP, which would be powerful candidates for a long-lived device. Some groups have also reported MgZnCdSebased light emittors on InP [4][5][6][7]. However, thus far no groups have succeeded in lasing-operation by the current injection scheme. This failure is due to the lack of suitable p-cladding materials for LDs. We have proposed a BeZnTe ternary alloy [8] and related materials [9, 10] as a new p-cladding layer and visible LEDs and LDs were successfully fabricated.In this paper, we describe LED and LD structures based on the II-VI materials grown on InP, as well as what structures might be suitable for visible LED and LD with these materials. We then explain our experimental results of the ZnCdSe single quantum well (SQW) LDs.