scholarly journals In-situ photo-modulated reflectance study on the interface of Al and GaAs surface quantum well

2004 ◽  
Vol 53 (10) ◽  
pp. 3521
Author(s):  
Yuan Xian-Zhang ◽  
Miao Zhong-Lin
Keyword(s):  
Quantum Well ◽  
Gaas Surface

Buried Quantum Well Structure Fabricated by in Situ EB Lithography

1991 ◽  
Vol 236 ◽  
Author(s):  
H. Kawanishi ◽  
Y. Sugimoto ◽  
T. Ishikawa ◽  
N. Tanaka ◽  
H. Hidaka
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Gaas Surface ◽  
Photoluminescence Intensity ◽  
Positive Type ◽  
Quantum Well Structures ◽  
Lithography Process ◽  
Order Of Magnitude ◽  
Processed Sample

AbstractBuried quantum well structures have been fabricated in GaAs/AIGaAs system using an in situ lithography process. The process utilizes an ultrathin oxide layer formed in situ on a GaAs surface as a mask against Cl2 gas etching. An electron beam (EB)-induced Cl2 gas etching is used to locally remove the oxide mask for positive-type lithography. For negativetype lithography, the oxide mask is selectively formed on a GaAs surface by EB-stimulated oxidation. Subsequent Cl2 gas etching results in the formation of isolated quantum wells. After removing the oxide mask, overgrowth using molecular beam epitaxy is successfully carried out on the patterned surface. The cathodoluminescence image of the buried quantum well demonstrates the high quality of the resulting structure formed by this “in situ EB lithography” process. The photoluminescence intensity from the quantum well of the processed sample is proved to be the same order of magnitude compared with that from a successively grown sample, showing that the use of the oxide mask causes no serious degradation in the processed interface.

scholarly journals Dimension control of in situ fabricated CsPbClBr2 nanocrystal films toward efficient blue light-emitting diodes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenhui Wang ◽  
Dengbao Han ◽  
Junhui Wang ◽  
Yingguo Yang ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Blue Emission ◽  
Light Emitting ◽  
Mixed Ligands ◽  
Dimension Control ◽  
Nanocrystal Films ◽  
Width Distribution ◽  
Quantum Well Width

AbstractIn the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr2 nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.

Passivation of III-V Semiconductor Surfaces Using Light Assisted Integrated Processes

1994 ◽  
Vol 342 ◽  
Author(s):  
Olivier Dulac ◽  
Yves I. Nissim
Keyword(s):  
Field Effect ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Surface Cleaning ◽  
Film Deposition ◽  
Gaas Surface ◽  
Nitride Film ◽  
Semiconductor Surfaces ◽  
Silicon Nitride Film

ABSTRACTPassivation of III-V semiconductor surfaces and especially the GaAs surface has been studied for over two decades without significant breakthrough. However, III-V device performances are still often limited by surface properties. In particular field effect behaviour in GaAs has been impossible to obtain due to the Fermi level pinning at the surface of this material. This paper presents an integrated sequence of low thermal budget processes to provide contamination control at the GaAs surface leading to very promising field effect on GaAs.In-situ surface cleaning using a Distributed Electron Cyclotron Resonance Microwave plasma (DECR MMP) has been integrated with a thin dielectric film deposition facility using light assisted CVD technics. Photoluminescence results carried out on GaAs surfaces have demonstrated that exposure to a hydrogen plasma induces lower recombination rates on these surfaces. Bulk diffusion of hydrogen during this process can be controlled and eliminated using an integrated Rapid Thermal Annealing (RTA). Finally, in-situ encapsulation by a dielectric allows one to stabilize the electronic properties of the surface for passivation applications. A silicon nitride film deposited by a direct UV photolysis deposition process has been developed for this study and is presented here.

In situ measurement method of GaAs surface coverage using secondary electron intensity

1991 ◽  
Vol 115 (1-4) ◽  
pp. 348-352 ◽  
Author(s):  
Kiyoshi Kanisawa ◽  
Jiro Osaka ◽  
Shigeru Hirono ◽  
Naohisa Inoue
Keyword(s):  
Measurement Method ◽  
Secondary Electron ◽  
Surface Coverage ◽  
In Situ Measurement ◽  
Gaas Surface ◽  
Electron Intensity

In Situ Flux Transient Monitoring and Correction During MBE Growth of Quantum Well Structures

1993 ◽  
Vol 300 ◽  
Author(s):  
F. G. Celii ◽  
Y.-C. Kao ◽  
A. J. Katz
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Effusion Cell ◽  
Multiple Quantum ◽  
Group V ◽  
Quantum Well Structures ◽  
Group Iii ◽  
Tunneling Diode ◽  
Partial Pressures

ABSTRACTShutter closure during MBE deposition causes source overheating and results in flux transients. These transients are particularly detrimental to the thickness and compositional accuracy of thin quantum well layers. In this paper, we document the effects of flux transients on growth of multiple quantum well (MQW) and resonant tunneling diode (RTD) structures, and demonstrate rudimentary transient correction by employing real-time flux detection.Reflection mass spectrometry (REMS) provides a convenient in situ method for MBE flux monitoring. The Group III partial pressures can be detected in the presence of Group V overpressure, and REMS is compatible with wafer rotation. We used REMS to characterize In, Al and Ga flux transients as a function of shutter closed time, cell flux and substrate temperature. Overshoot magnitudes up to 30% were observed. We verified the correspondence of REMS signal transients and effusion cell flux transients using GaAs/AlGaAs and InGaAs/lnAlAs MQW and test structures. We also successfully demonstrated flux transient correction by cell temperature ramping during MQW and RTD growth.

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