APSYS 參數問題

Q:想請問 crosslight.mac 與 more.moc差別在哪裡 ?

Q:關於參數的設定不能從 mac 檔直接改嗎 ? 一定要從 sol 設定嗎 ?p.s 因為 在校的指導老師認為參數的值跟大多數 paper 看到的有些出入

Q:value= 50.e-12 ,e-12 的意思是指 10-

12

那value=1.d5, d 指的是什麼意思 ?

GaN AlN

Q:關於 GaN 和 AlN 的 lifetime 好像有些出入

Q:關於 LED 其 GaN 的材料為六方晶結構，而參數所設 Eg 的band_gap 上可能有些許落差，這邊不知道能不能直接換上我們要的值。

• lifetime_n

The material statements lifetime_n and lifetime_p define the minority life time (in seconds) for carriers (_n for electrons and _p for holes) in the SRH recombination model. The basic mechanism is electron or hole capture by deep level traps. This statement is therefore related to other trap statements. The relation between lifetime and other trap quantities are written as:

1/lifetime= trap density × thermal velocity × capture cross section

• radiative_recomb

radiative_recomb is the radiative (or spontaneous) recombination coefficient in units of m3∕sec. It is usually defined as the coefficient B such that the radiative recombination is given by B(np - ni) where ni is the intrinsic carrier density. Note that this coefficient is only used for the non-active region of the laser. For active regions, the spontaneous emission rate is computed from first principles, analogous to the optical gain.

• absorption

This material statement is used to defined the optical absorption or loss (in units of 1/m) in passive materials of the device. For active materials, this value is overridden by the internal gain calculations.

The default macro setting for this parameter is zero which means that a default background loss will be applied for this material. This background loss will be determined either by a hard-coded value in the software or from the backg_loss value in init_wave or set_wavelength. Note that conversely, a non-zero value of absorption will override the background loss for this material.

• real_index

The material statement real_index is the real refractive index at the appropriate optical frequency. Please do not confuse this with the dielectric constant of Poisson’s equation at DC or low frequencies.

The parameters for this statement are the same as for all other material statements. The use of these parameters and related examples are given under material_par in section 22.401.

• tau_energy

tau_energy is the energy relaxation time of hot electrons in seconds. It is used only when hot electron model is activated.

• norm_field• The material parameter norm_field is added to the

list of parameters in the material library. It is used if “n.gaas” is chosen as the type of field-dependent mobility, as the normalizing field (F0n) (see the User’s Manual). It allows the user to specify more accurate electron mobility as a function of field in III-V or II-VI materials, where the Gamma to L and Gamma to X bands cause the velocity vs. field relation to exhibit a negative slope.

• beta_n• beta_n defines a parameter in the “beta” field-

dependent mobility model for electrons

• beta_mte• beta_mte is used in the modified transferred-

electron mobility model for GaN.

• electron_sat_vel

The material statement electron_sat_vel is used to define the saturation electron velocity (in m/s). It is used in Eq. 5.39 to define the field-dependent mobility function.

The parameters for this statement are the same as for all other material statements. . See material_par in section 22.401 for examples and further details.

• affinity• affinity is a passive macro material statement

defining the electron affinity (in eV) of a material. In metal and resistors, this value is equal to the work function: it is the difference between the vacuum level and the conduction band edge. For active layers, affinity will be overridden by band offset parameters from the active macro.

• a_bulk• The material statement a_bulk is a passive

macro statement used to define the total hydrostatic deformation potential (eV) in a wurtzite bulk region. This value is split between the conduction and valence bands according to ac_bulk.

• ac_bulk• The material statement ac_bulk is a passive

macro statement used to define the hydrostatic deformation potential (eV) applied to the conduction band in wurtzite bulk regions

• d1_bulk• di_bulk,i=1...6 are a set of parameters used to

define barrier properties in wurtzite passive macros. They define the shear deformation potential (di) as defined in Ref [74].

• The parameters for this statement are the same as for all other material statements

• c11_bulk• cij_bulk are a set of statements defining the

stiffness tensor (elastic constants) in a passive material macro. This is only used for wurtzite materials since the software does not support strained bulk zincblende.

• e15_bulk • e15_bulk and related commands are used in a

passive macro (wurtzite only) to define piezoelectric tensor components

• shal_acpt_level• shal_acpt_level is used to define or override

the shallow acceptor level of the p-type dopants. The level is measured from the valence band and in the unit of eV.

• thermal_kappa• thermal_kappa defines the thermal

conductivity κ (in W/(m*K)) for a given material. This is used to solve the heat flow equation and is otherwise ignored.