Interface roughness and alloy‐disorder scattering contributions to intersubband transition linewidths

1996 ◽  
Vol 69 (17) ◽  
pp. 2554-2556 ◽  
Author(s):  
K. L. Campman ◽  
H. Schmidt ◽  
A. Imamoglu ◽  
A. C. Gossard
2013 ◽  
Vol 873 ◽  
pp. 777-782
Author(s):  
Qian Feng ◽  
Peng Shi ◽  
Jie Zhao ◽  
Kai Du ◽  
Yu Kun Li ◽  
...  

We presented a theoretical study of the dependence of 2DEG mobility on temperature, barrier thickness, Al content, donor concentration to reveal the internal physics of 2DEG mobility in cubic AlGaN/GaNheterostructures. The 2DEG mobility is modeled as a combined effect of the scattering mechanisms including acoustic phonons, ionized impurity, dislocation, alloy disorder and interface roughness scattering.The variation of mobility results mainly from the change of 2DEG density and temperature. It reveals the dominant scattering mechanismsare dislocation and alloy disorder scattering atlow temperature.Acoustic phonons scattering becomes the major limit at 300k. Impurity scattering plays the key role when donor density rises. We find a maximum mobility with a structure of 25% Al content and 4-5nm barrier thickness.


2011 ◽  
Vol 181-182 ◽  
pp. 364-369
Author(s):  
Cheng Wang ◽  
He Ming Zhang ◽  
Rong Xi Xuan ◽  
Hui Yong Hu

Si-based strained technology is currently an important topic of concern in the microelectronics field. The stress-induced enhancement of electron mobility contributes to the improved performance of Si-based strained devices. In this paper, Based on both the electron effective mass and the scattering rate models for strained-Si1-xGex/Si (101), an analytical electron mobility model for biaxial compressive strained-Si1-xGex /Si (101) is presented. The results show that the stress doesn’t make the electron mobility increased, but the electron mobility for [100] and [001] orientations decrease with increasing Ge fraction x, especially for [010] orientation expresses a sharp decrease. This physical phenomenon can be explained as: Although the applied stress (the higher the Ge fraction, the greater the applied stress) can enhance the electron mobility, alloy disorder scattering rate markedly increase. Overall the electron mobility decreases instead. The above result suggests that not all the mobilities for Si-based strained materials enhance with the stress applied. For the biaxial strained-SiGe material represented by Ge fraction, the effect of alloy disorder scattering on the enhancement of mobility must be concerned. The result can provide theoretical basis for the understanding of the improved physical characterizations and the enhanced mobility for Si-based strained materials.


2020 ◽  
Vol 54 (7) ◽  
pp. 676
Author(s):  
S.R. Panda ◽  
A. Sahu ◽  
S. Das ◽  
A.K. Panda ◽  
T. Sahu

We analyze the asymmetric delta-doping dependence of nonlinear electron mobility μ of GaAs|InxGa1-xAs double quantum-well pseudo-morphic modulation doped field-effect transistor structure. We solve the Schrodinger and Poisson's equations self-consistently to obtain the sub-band energy levels and wave functions. We consider scatterings due to the ionized impurities (IMP), alloy disorder (AL), and interface roughness (IR) to calculate μ for a system having double sub-band occupancy, in which the inter-sub-band effects play an important role. Considering the doping concentrations in the barriers towards the substrate and surface sides as Nd1 and Nd2, respectively, we show that variation of Nd1 leads to a dip in μ near Nd1=Nd2, at which the resonance of the sub-band states occurs. A similar dip in μ as a function of Nd1 is also obtained at Nd1=Nd2 by keeping (Nd1+Nd2) unchanged. By increasing the central barrier width and well width, the dip in μ becomes sharp. We note that even though the overall μ is governed by the IMP- and AL-scatterings, the dip in μ is mostly affected through substantial variation of the sub-band mobilities due to IR-scattering near the resonance. Our results of nonlinear electron mobility near the resonance of sub-band states can be utilized for the performance analysis of GaAs|InGaAs pseudo-morphic quantum-well field-effect transistors. Keywords: asymmetric double quantum wells, GaAs|InxGa1-xAs structures, nonlinear electron mobility, pseudo-morphic HEMT structures, resonance of sub-band states.


2011 ◽  
Vol 403-408 ◽  
pp. 64-69
Author(s):  
Md. Sherajul Islam ◽  
Md. Arafat Hossain ◽  
Sakib Mohammed Muhtadi ◽  
Ashraful G. Bhuiyan

As a promising candidate for future high speed devices InN-based heterojunction field effect transistor (HFET) has gained a lot of attention in recent years. However, InN-based devices are still a less studied compared with other III-nitride based devices. This work investigates theoretically, the electron transport properties of insulated gate AlInN/InN Heterojunction Field Effect Transistor. A self-consistent charge control model based on one-dimensional Schrodinger-Poisson equations is developed. The transport properties of the device are calculated using an ensemble Monte Carlo simulation. The device model incorporates an analytical 3-valley band structure with non-parabolicity for all nitride materials. The scattering mechanisms considered are dislocations scattering, impurity scattering, interface roughness, alloy disorder scattering and phonon scattering. The model also takes into account the highly dominant spontaneous and piezoelectric polarization effects to predict the 2DEG sheet charge density more accurately at the heterointerface. The results obtained are agreed well with the literature.


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