Investigation of p‐contact layers for BeZnSeTe/MgZnCdSe optical devices on InP substrates

Abstract

ZnTe and ZnSeTe p‐contact layers were investigated for use in BeZnSeTe/MgZnCdSe optical devices on InP sub‐strates. The contact resistances (Rc) of Au electrodes to N‐doped p‐ZnTe and p‐ZnSeTe contact lay‐ers were evaluated using the circular transmission line model (c‐TLM) method. A lower Rc (3.1×10‐3 Ωcm2) was obtained for the ZnSeTe p‐contact sample than for the ZnTe sample (6.3×10‐3 Ωcm2). BeZnSeTe/MgZnCdSe yellow‐light‐emitting devices with a ZnTe or ZnSeTe p‐contact layer grown on InP substrates were characterized. A comparison of the current‐voltage (I‐V) characteristics of these devices showed that the turn‐on voltage of the ZnSeTe contact device was about 4 V lower than that of the ZnTe device. From the aging characteristics of these devices under direct‐current injection at room temperature, it was shown that the lifetime of the ZnSeTe contact device was 30 times longer than that of the ZnTe contact device. These results show that a ZnSeTe contact layer is more suitable for BeZnSeTe/MgZnCdSe optical devices on InP substrates than a ZnTe contact layer. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Application of indium tin oxide to the p‐cladding layers of yellow/green II‐VI compound semiconductor laser diode structures on InP substrates

“…1(a) and (b), to calculate the optical field distributions in the waveguides. The first LD structure was a conventional structure; it is a separate confinement heterostructure (SCH) comprising an undoped BeZnTe (1 monolayer (ML))/ZnSeTe (9 ML) SL (30 nm) active layer sandwiched between an un-MgSe (4 ML)/BeZnTe (6ML) SL (9 nm) p-side barrier layer and an un-MgSe (4ML)/BeZnTe (4 ML) SL (50 nm) n-side barrier layer, un-MgSe/ZnCdSe graded SL (61 nm) layer, n-MgSe (2 ML)/ZnCdSe (4 ML) SL (500 nm) n-cladding layer, and a p-MgSe (4 ML)/BeZnTe (6 ML) SL (600 nm) p-cladding layer [13]. The configuration of the second LD structure was the same as that of a conventional structure except for an ITO layer (400 nm) for the SL p-cladding layer, p-BeZnTe (20 nm), and p-ZnTe/BeZnTe SL (5 nm).…”

“…p-ZnTe (30 or 5 nm) p-contact layers were embedded in both structures. The graded SL was introduced to reduce the influence of the hetero barrier for electron injections at the interface between the n-side barrier and the n-cladding layers [13]. The ZnTe/BeZnTe SL and ZnTe p-contact layers of the ITO LD structure were embedded to reduce the contact resistance between the II-VI layers and ITO, and to inject holes into the active layer.…”

“…1 Introduction II-VI compound semiconductors on InP substrates are promising materials for yellow/green laser diodes (LDs) and light emitting diodes (LEDs) [1][2][3][4][5][6][7][8][9][10][11][12][13]. We are developing II-VI devices on InP substrates based on a device structure comprising a BeZnTe/ZnSeTe superlattice (SL) active layer, MgSe/ZnCdSe SL n-cladding layer, and MgSe/BeZnTe SL p-cladding layer [13].…”

“…We are developing II-VI devices on InP substrates based on a device structure comprising a BeZnTe/ZnSeTe superlattice (SL) active layer, MgSe/ZnCdSe SL n-cladding layer, and MgSe/BeZnTe SL p-cladding layer [13]. BeZnTe/ZnSeTe SLs exhibit bandgap energies ranging from 2.11 to 2.48 eV, corresponding to the wavelength range from 500 to 585 nm under the lattice-matching with InP [12].…”

Investigation of p-side contact layers for II–VI compound semiconductor optical devices fabricated on InP substrates by MBE

“…The electrode geometry and size and the calculation method of R c were the same as those in Ref. [15].…”