JP2503859B2 - Semiconductor light emitting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device having an oscillation wavelength in the blue to infrared wavelength band.

[0002]

2. Description of the Related Art Recently, a blue-green semiconductor laser using a II-VI group semiconductor has been realized. One of them is ZnCdS
It uses a Se-based semiconductor (Applied Physics Letters [Applied Physics
Letters] 60: 2045, 1992).
This semiconductor laser consists of (Zn, Cd) on a GaAs substrate.
Se / Zn (S, Se) quantum well active layer is n-type Zn
It has a structure formed by being sandwiched between (S, Se) and P-type Zn (S, Se) cladding layers.

The other is a ZnMgSSe based semiconductor (Proceedings of the 53rd JSAP Academic Lecture Meeting, page 1223). This semiconductor laser is Ga
Laser oscillation is obtained by photoexcitation in a structure in which a ZnSSe active layer is sandwiched between ZnMgSSe cladding layers on an As substrate.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The dSSe-based blue-green semiconductor laser has a problem in that the active layer contains strain and carrier confinement is possible, but it is weak, optical confinement is not possible, and a double hetero structure cannot be manufactured. In addition, a ZnMgSSe-based semiconductor laser can form a double hetero structure, but Mg that is easily oxidized is used.
However, it has a problem that it is not stable as a device.

An object of the present invention is to provide a semiconductor light emitting device having a double hetero structure which uses a stable material as a device and has sufficient band discontinuity.

[0006]

According to the present invention, there is provided a first cladding layer made of a II-VI semiconductor having a first conductivity type and a second cladding layer made of a II-VI semiconductor having a second conductivity type. In a semiconductor light emitting device having an active layer sandwiched with a clad layer, the semiconductor forming the active layer is II-VI.
It is characterized by comprising a mixed crystal of a group III semiconductor and a group III-V semiconductor. Further, according to the present invention, a first cladding layer made of a mixed crystal of a II-VI group semiconductor having a first conductivity type and a III-V semiconductor and a second cladding layer having a second conductivity type are used.
In a semiconductor light emitting device having an active layer sandwiched between a second cladding layer made of a mixed crystal of a group-VI semiconductor and a group III-V semiconductor, the semiconductor constituting the active layer is II-V.
A semiconductor light emitting device is obtained which is composed of a mixed crystal of a group I semiconductor and a group III-V semiconductor.

[0007]

In the present invention, in order to efficiently generate visible light emission from blue to orange in the 0.4 to 0.5 μm band, I
Group I-VI Semiconductor, Group II-VI Semiconductor and Group III-V
By using a mixed crystal of a group semiconductor, the variable range of the bandgap energy of the active layer is widened, and the active layer is sandwiched by the clad layers having a bandgap energy sufficiently wider than that of the active layer to form a semiconductor device having a double hetero structure. Configured.

In the II-VI group semiconductor and the III-V group semiconductor, the bandgap energy with respect to the lattice constant is smaller in the III-V group semiconductor, and by forming a mixed crystal, the cladding layer and the active layer are separated under the lattice matching condition. The band gap energy difference between
It turns out that carrier confinement becomes possible. Further, the optical permittivity (refractive index) has a relationship that increases as the band gap energy becomes smaller, so that optical confinement becomes possible. Therefore, a double hetero structure can be formed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. The basic structure of the semiconductor light emitting device according to the first embodiment of the present invention is shown in FIG. An n-type II-VI clad layer 11 (thickness 1 μm, n = 1 × 10) made of ZnS _0.08 Se _0.92 added with Cl on a substrate 10 made of n-type GaAs.
¹⁸ cm ⁻³ ) and (ZnSe) _0.90 (GaAs) _0.10 active layer 12 (thickness 10 nm), N-doped ZnS _0.08
A P-type II-VI clad layer 13 made of Se _0.92 (thickness 1 μm, p = 5 × 10 ¹⁷ cm ⁻³ ) was grown, and a P electrode 14 made of Au (thickness 300 nm) and an n electrode 15 made of In ( (Thickness 300 nm) is formed by a vacuum evaporation method,
A semiconductor laser device was manufactured by forming a reflecting surface by cleavage.

The band gap energy of the cladding layers 11 and 13 is 2.70 eV, the band gap energy of the active layer 12 is 2.27 eV, and the oscillation wavelength is 534.
In nm, GaAs has a larger refractive index than ZnSe, and a sufficient difference in refractive index and bandgap energy difference for producing a double heterojunction structure semiconductor laser can be obtained. In this way, a green semiconductor laser could be realized by the material and structure having the constitution of this embodiment.

FIG. 2 is a sectional view showing a semiconductor light emitting device according to the second embodiment of the present invention. n-type (ZnSe) _0.86 with Li as a dopant on the substrate 20 made of n-type GaAs
(GaAs) _0.14 clad layer 21 (thickness 1μ
m, n = 1 × 10 ¹⁸ cm ⁻³ ) and (ZnSe) _0.60 (Ga
As) _0.40 active layer 22 (thickness 10 nm), Cl
N-type (ZnSe) _0.86 (GaAs)
Clad layer 23 made of _0.14 (thickness 1 μm, P = 1 × 1
0 ¹⁸ cm ^- 3) is grown, P electrode 24 made of Au (thickness 300 nm), n electrode 25 made of In (thickness 300n
m) is formed by a vacuum evaporation method, and a reflective surface is formed by cleavage.

The band gap energy of the clad layers 21 and 23 is 2.23 eV, the band gap energy of the active layer 22 is 1.80 eV, and the refractive index of GaAs is larger than that of ZnSe at the oscillation wavelength of 688 nm, and the double heterojunction. A refractive index difference and a bandgap energy difference sufficient to manufacture a structured semiconductor laser can be obtained. A red semiconductor laser was realized by the material structure having the configuration of this example. It should be noted that the numerical values described in the above embodiments are examples, and the present invention is not limited to these.

[0013]

As described above, according to the present invention,
There is an effect that a semiconductor laser device or a semiconductor light emitting device which has a double hetero structure and emits light in the blue to infrared wavelength band which is stable and has a long life can be obtained. In particular, the visible light emission from blue to orange is obtained, so that it can be used as a light source for high density optical discs and multicolor LE.
It can be applied to D substitute light source and high sensitivity laser printer light source.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 10, 20 substrate 11 n-type II-VI clad layer 12, 22 II-VI, III-V mixed crystal active layer 13 p-type II-VI clad layer 14, 24 p electrode 15, 25 n-electrode 21 n-type II-VI , III-V mixed crystal clad layer 23 p-type II-III-V mixed crystal clad layer

Claims (2)

(57) [Claims] 1. A first clad layer made of a II-VI group semiconductor having a first conductivity type and an I having a second conductivity type.
In a semiconductor light emitting device having an active layer sandwiched between a second cladding phase made of a I-VI group semiconductor, the semiconductors forming the active layer are a II-VI group semiconductor and a III- group semiconductor.
A semiconductor light-emitting device comprising a mixed crystal with a group V semiconductor. 2. A first cladding layer made of a mixed crystal of a II-VI group semiconductor having a first conductivity type and a III-V semiconductor, and a II-VI group semiconductor having a second conductivity type and II.
In a semiconductor light emitting device having an active layer sandwiched between a second clad layer made of a mixed crystal of a IV semiconductor, a semiconductor constituting the active layer includes a II-VI semiconductor and an I-VI semiconductor.
A semiconductor light-emitting device comprising a mixed crystal of a II-V group semiconductor.