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Henry Lee

Parameters for GaAs

I just wondering the parameters or the refernce for calculation of GaAs in Schred. Including the orientation, degenerate number, effective quantum mass, effective density of state mass, etc.


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    Gokula Kannan

    Hi Lee, I assume you are asking for the simulation using Schred V2.0 The following are the parameters for the QM simulation of GaAs for that tool:

    Transport orientation = width orientation = confinement orientation = Gamma valley eff. mass (mx=my=mz) = 0.06574 L valley eff. mass: mx= 1.72750 ; my= 0.09671; mz=0.09671 X valley eff.mass: mx=1.88076; my=0.17525; mz=0.17525 Heavy hole eff. mass (same for all 3 valleys) = 0.51 Light hole eff. mass (same for all 3 valleys)= 0.082 valley offset : Gamma = 0 ; L-valley = 0.29; X-valley=0.48 valley degeneracy: Gamma = 1.0; L-valley = 4.0; X-valley = 3.0

    Do not worry about the eff. DOS mass etc, they are calculated in the program using the principal effective masses of the three valleys.

    Hope this helps, Thanks, Gokul

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    Gokula Kannan

    1.Is mz for L/X valley the mass along 111/100 direction?- the directions mentioned in the simulator are the device directions (transport/width/confinement orientation etc), the orientation that you have mentioned are the ellipsoidal(/crystallographic) directions for each of the valleys. 2.Why is not the degenerate number for L valley 8 instead of 4? Why is not the degenerate number for X valley 6 instead of 3?- we consider valley pairs, hence the degeneracy by 2 3.In your reply “Heavy hole eff. mass (same for all 3 valleys) = 0.51”, should it be “same for 3 subbands”. If it’s not, may I beg for the reason.- yes Schred takes the same hole effective mass, to calculate the valence band DOS- used to calculate the final carrier concentration. 4.Is 0.51/0.082 the quantized mass for heavy/light hole? What is the mass of density of mass for them?- It is the effective mass for the bulk GaAs – HH & LH valence bands. 5.Does Schred consider bandgap narrowing when temperature or doping concentration change?-No, it does not consider BGN. 6.By the way, can you recommand some good reference for GaAs.I find very less information about subband calculation of GsAs, so I bother you for many questions. Thank you!- Yang, T., et al. “Inversion Capacitance-Voltage Studies on GaAs Metal-Oxide-Semiconductor Structure using Transparent Conducting Oxide as Metal Gate.” Applied Physics Letters 92 (2008): 252105, I used this to compare my results with, you can check their parameters for their simulation.

    hope this helps!

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