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1.
AlGaInP light-emitting diode with tensile strain barrier reducing layer   总被引:1,自引:0,他引:1  
A novel tensile strain barrier reducing (TSBR) structure is grown between the window and cladding layers of multi-quantum-well (MQW)-AlGaInP light-emitting diodes (LEDs). The TSBR film (100/spl sim/200 /spl Aring/ of Ga/sub 0.65/In/sub 0.35/P) is of lattice size and valence band energy intermediate between those of window and cladding layers, thus reducing band offset and decreasing device forward bias from 2.55 V to 1.92 V at 20 mA, with concomitant improvements in dynamic resistance and junction heating. The TSBR layer increases power efficiency by 30% at 20 mA and up to 65% at high current conditions. The reduced junction heating of the with-TSBR design may be of significant advantage to device quality, reliability and lifetime, especially for high current applications.  相似文献   

2.
A high-reliability multiple quantum-well AlGaInP light-emitting diode is grown by inserting a novel tensile strain barrier-reducing (TSBR) structure between the window and cladding layers. The TSBR (/spl sim/150 /spl Aring/ of Ga/sub 0.65/In/sub 0.35/P) film is of lattice size with valence band energy and is located between window and cladding layers, thus, significantly reducing band offset and device forward bias, and accordingly achieves improvement in dynamic resistance and junction heating. Reducing junction heating significantly enhances device reliability and lifetime. The TSBR layer also acts as a buffer layer, reducing band, and junction discontinuity between the misfit layers, an effect that can be attributed to reduced nonradiative recombination and defect density. Accordingly, TSBR is a successful design for improving global life behavior.  相似文献   

3.
The properties of doped-channel field-effect transistors (DCFET) have been thoroughly investigated on Al/sub x/Ga/sub 1-x/As/InGaAs (x= 0.3, 0.5, 0.7, 1) heterostructures with various Al mole fractions. In this study, we observed that by introducing a 200-/spl Aring/-thick Al/sub 0.5/Ga/sub 0.5/As (x=0.5) Schottky layer can enhance the device power performance, as compared with the conventional x=0.3 AlGaAs composition system. However, a degradation of the device power performance was observed for further increasing the Al mole fractions owing to their high sheet resistance and surface states. Therefore, Al/sub 0.5/Ga/sub 0.5/As Schottky layer design provides a good opportunity to develop a high power device for power amplifier applications.  相似文献   

4.
This paper proposes a In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As (x=0.3-0.5-0.3) metamorphic high-electron mobility transistor with tensile-strained channel. The tensile-strained channel structure exhibits significant improvements in dc and RF characteristics, including extrinsic transconductance, current driving capability, thermal stability, unity-gain cutoff frequency, maximum oscillation frequency, output power, power gain, and power added efficiency.  相似文献   

5.
The properties of both lattice-matched and strained doped-channel field-effect transistors (DCFET's) have been investigated in AlGaAs/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) heterostructures with various indium mole fractions. Through electrical characterization of grown layers in conjunction with the dc and microwave device characteristics, we observed that the introduction of a 150-/spl Aring/ thick strained In/sub 0.15/Ga/sub 0.85/As channel can enhance device performance, compared to the lattice-matched one. However, a degradation of device performance was observed for larger indium mole fractions, up to x=0.25, which is associated with strain relaxation in this highly strained channel. DCFET's also preserved a more reliable performance after biased-stress testings.<>  相似文献   

6.
In/sub 0.425/Al/sub 0.575/As-In/sub x/Ga/sub 1-x/As metamorphic high electron mobility transistors (MHEMTs) with two different channel designs, grown by molecular beam epitaxy (MBE) system, have been successfully investigated. Comprehensive dc and high-frequency characteristics, including the extrinsic transconductance, current driving capability, device linearity, pinch-off property, gate-voltage swing, breakdown performance, unity-gain cutoff frequency, max. oscillation frequency, output power, and power gain, etc., have been characterized and compared. In addition, complete parametric information of the small-signal device model has also been extracted and discussed for the pseudomorphic channel MHEMT (PC-MHEMT) and the V-shaped symmetrically graded channel MHEMT (SGC-MHEMT), respectively.  相似文献   

7.
A novel top-illuminated In/sub 0.53/Ga/sub 0.47/As p-i-n photodiodes (MM-PINPD) grown on GaAs substrate by using linearly graded metamorphic In/sub x/Ga/sub 1-x/P (x graded from 0.49 to 1) buffer layer is reported. The dark current, optical responsivities, noise equivalent power, and operational bandwidth of the MM-PINPD with aperture diameter of 60 /spl mu/m are 13 pA, 0.6 A/W, 3.4/spl times/10/sup -15/ W/Hz/sup 1/2/, and 7.5 GHz, respectively, at 1550 nm. The performances of the MM-PINPD on GaAs are demonstrated to be comparable to those of a similar device made on InGaAs-InP substrate.  相似文献   

8.
Double heterojunction bipolar transistors based on the Al/sub x/Ga/sub 1-x/As/GaAs/sub 1-y/Sb/sub y/ system are examined. The base layer consists of narrow band gap GaAs/sub 1-y/Sb/sub y/ and the emitter and collector consist of wider band gap Al/sub x/Ga/sub 1-x/As. Preliminary experimental results show that AlGaAs/GaAsSb/GaAs DHBTs exhibit a current gain of five and a maximum collector current density of 5*10/sup 4/ A/cm/sup 2/.<>  相似文献   

9.
A GaAs/Al/sub x/Ga/sub 1-x/As multiple quantum well laser with an electrical modulation bandwidth exceeding 15 GHz has been fabricated. Optimised design of the waveguide, including development of high Al mole fraction (x=0.8) cladding layers, together with a coplanar electrode geometry, has resulted in a vertically compact laser structure suitable for integration.<>  相似文献   

10.
The first demonstration of distributed feedback InGaAs-GaAs buried heterostructure strained quantum well lasers with In/sub 0.49/Ga/sub 0.51/P cladding layers entirely grown by a three step MOVPE process is reported. Uncoated distributed feedback buried heterostructure lasers with a pn InGaP current blocking junction on a p/sup +/-GaAs substrate show a low laser threshold of 3.2 mA and a high output power of 45 mW both measured CW at RT.<>  相似文献   

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