AlGaInAs material model

1. Introduction

This page contains the OghmaNano material model for AlGaInAs (AlGaInAs).

(AlxGa1-x)0.47In0.53As on InP, x = Al ~ 0.30 (direct gap)

The model is written in Lua and provides simulation-ready material parameterisations for use within OghmaNano. For documentation, licensing, references, and information about the scope and accuracy of these models, see the material scripting documentation.

2. Lua material model

Supporting definitions

-- See end of file for copyright, licensing and documentation links.

local material = {}

-- ---------------------------------------------------------------------------
-- NOTES ON AlGaInAs (read before using):
--
-- (Al_x Ga_{1-x})_{0.47} In_{0.53} As, LATTICE-MATCHED to InP (a = 5.869 A). The
-- workhorse quaternary for 1.3-1.55 um telecom lasers, modulators and
-- photodetectors. In is fixed at 0.53 for the InP match, so the single design
-- knob is the Al fraction x on the group-III sublattice.
--
-- DIRECT gap for all x (no crossover in the useful range): ~0.75 eV at x=0
-- (Ga0.47In0.53As, "InGaAs", ~1.65 um) rising to ~1.46 eV at x=1
-- (Al0.48In0.52As, ~0.85 um). Compared with the older InGaAsP telecom
-- quaternary, AlGaInAs offers a larger conduction-band offset (better electron
-- confinement), which is why it is favoured for high-temperature laser
-- operation - a device advantage, captured here only via Xi/Eg.
--
-- The lattice constant is FIXED by the InP match (independent of x). Eg is
-- computed from x; the remaining parameters are given at a representative
-- x = 0.30 (Eg ~ 0.92 eV, ~1.34 um) with InGaAs/AlInAs end points noted.
--
-- REFERENCES
--
-- [1]  I. Vurgaftman, J. R. Meyer, L. R. Ram-Mohan, J. Appl. Phys. 89, 5815
--      (2001). [constituent band parameters, bowing]
-- [2]  S. Adachi, "Properties of Semiconductor Alloys", Wiley (2009); and
--      S. Adachi, "Physical Properties of III-V Semiconductor Compounds"
--      (1992). [Eg(x), transport, dielectric, thermal]
-- [3]  O. Madelung, "Semiconductors: Data Handbook", Springer (2004).
-- ---------------------------------------------------------------------------

function material.name()
	local enabled = true

	return "AlGaInAs", enabled
end

function material.description()
	local enabled = true

	return "(AlxGa1-x)0.47In0.53As on InP, x = Al ~ 0.30 (direct gap)", enabled
end

function material.formula()
	local enabled = true

	return "AlGaInAs", enabled
end

function material.Eg(state)
	-- Units: eV
	-- Refs: [1],[2]
	--
	-- Direct gap, lattice-matched to InP, in Al fraction x. 300 K relation
	-- [2]:  Eg(x) = 0.76 + 0.49*x + 0.20*x^2
	-- (0.76 eV at x=0 -> 1.45 eV at x=1). Temperature handled by a
	-- Varshni-type shift about 300 K (alpha = 4.0e-4 eV/K, beta = 200 K).
	-- x = 0.30 -> ~0.925 eV (~1.34 um) at 300 K. Change al_fraction here
	-- and in the functions noted in the header.

	local enabled = true
	local al_fraction = 0.30
	local x = al_fraction
	local T = state.T
	local eg_300 = 0.76 + 0.49*x + 0.20*x*x
	local tshift = 4.0e-4*(90000.0/500.0 - T*T/(T + 200.0))
	local value = eg_300 + tshift

	return value, enabled
end

function material.Xi(state)
	-- Electron affinity
	-- Units: eV
	-- Refs: [2],[3]
	--
	-- ~4.45 eV at x = 0.30. Falls with Al (InGaAs ~4.6 -> AlInAs ~4.1 eV);
	-- the resulting large conduction-band offset to InP / across the alloy
	-- is the key confinement advantage over InGaAsP.

	local enabled = true
	local value = 4.45

	return value, enabled
end

function material.me(state)
    local enabled = true
    local x = state.x     -- Al/(Al+Ga) in (AlxGa1-x)0.48In0.52As (InP-LM, direct)
    -- Gamma mass, Ga0.47In0.53As 0.041 -> Al0.48In0.52As 0.075
    local value = 0.041 + 0.034*x
    return value, enabled
end

function material.mh(state)
    local enabled = true
    local x = state.x
    -- HH[001]: 0.34 -> 0.40 (interpolated endpoints)
    local value = 0.34 + 0.06*x
    return value, enabled
end

function material.Nc(state)
	-- Effective conduction-band density of states
	-- Units: m^-3
	-- Refs: [2],[3]
	--
	-- ~4e23 m^-3 at 300 K for x = 0.30 (small direct-valley mass, m_e* ~
	-- 0.05-0.07 m0). Endpoints: InGaAs ~2.1e23, AlInAs ~5.4e23 m^-3.

	local enabled = true
	local T = state.T
	local value = 4.0e23*(T/300.0)^1.5

	return value, enabled
end

function material.Nv(state)
	-- Effective valence-band density of states
	-- Units: m^-3
	-- Refs: [2],[3]
	--
	-- ~8e24 m^-3 at 300 K for x = 0.30 (InGaAs ~7.7e24, AlInAs ~9e24 m^-3).

	local enabled = true
	local T = state.T
	local value = 8.0e24*(T/300.0)^1.5

	return value, enabled
end

function material.mu_e(state)
	-- Low-field electron mobility
	-- Units: m^2 V^-1 s^-1
	-- Refs: [2]
	--
	-- ~0.3 m^2/V/s (3000 cm^2/V/s) at x = 0.30 - high (small mass) but
	-- alloy-scattering-reduced from InGaAs (~10000-13000 cm^2/V/s) toward
	-- AlInAs (~1000-4000 cm^2/V/s). (300/T)^1.5 approximate.

	local enabled = true
	local T = state.T
	local value = 0.30*(300.0/T)^1.5

	return value, enabled
end

function material.mue_x(state)
	return material.mu_e(state)
end

function material.mue_y(state)
	return material.mu_e(state)
end

function material.mue_z(state)
	return material.mu_e(state)
end

function material.mu_h(state)
	-- Low-field hole mobility
	-- Units: m^2 V^-1 s^-1
	-- Refs: [2]
	--
	-- ~0.02 m^2/V/s (200 cm^2/V/s) at x = 0.30 (InGaAs ~300, AlInAs ~100
	-- cm^2/V/s). (300/T)^1.5 approximate.

	local enabled = true
	local T = state.T
	local value = 0.02*(300.0/T)^1.5

	return value, enabled
end

function material.muh_x(state)
	return material.mu_h(state)
end

function material.muh_y(state)
	return material.mu_h(state)
end

function material.muh_z(state)
	return material.mu_h(state)
end

function material.epsilonr(state)
	-- Relative static permittivity
	-- Dimensionless
	-- Refs: [2],[3]
	--
	-- ~13.4 at x = 0.30 (InGaAs ~13.9 -> AlInAs ~12.5).

	local enabled = true
	local value = 13.4

	return value, enabled
end

function material.free_to_free_recombination(state)
	-- Radiative recombination coefficient
	-- Units: m^3 s^-1
	-- Refs: representative (see note)
	--
	-- Direct-gap value ~1e-10 cm^3/s = 1e-16 m^3/s. Representative; refine
	-- against measured lifetimes.

	local enabled = true
	local value = 1.0e-16

	return value, enabled
end

function material.auger_Cn(state)
	-- Electron Auger recombination coefficient
	-- Units: m^6 s^-1
	-- Refs: representative (see note)
	--
	-- ~2e-28 cm^6/s = 2e-40 m^6/s at the InGaAs-rich (narrow-gap) end.
	-- Auger is a major loss mechanism in 1.55 um AlGaInAs/InGaAsP lasers
	-- and grows sharply as x decreases (gap narrows) - scale accordingly.

	local enabled = true
	local value = 2.0e-40

	return value, enabled
end

function material.auger_Cp(state)
	-- Hole Auger recombination coefficient
	-- Units: m^6 s^-1
	-- Refs: representative (see note)
	--
	-- As auger_Cn: representative 2e-28 cm^6/s = 2e-40 m^6/s.

	local enabled = true
	local value = 2.0e-40

	return value, enabled
end

function material.ss_srh_trap_energy(state)
	-- SRH trap energy relative to the middle of the band gap.
	-- Units: eV
	--
	-- Positive values are above mid-gap (towards the conduction band).
	-- Negative values are below mid-gap (towards the valence band).
	--
	-- Defect-dependent. Lattice-matched InP-based material can be very high
	-- quality; set level and density from your own data. Mid-gap default.

	local enabled = true
	local value = 0.0

	return value, enabled
end

function material.ss_srh_Nt(state)
	-- SRH trap density
	-- Units: m^-3
	--
	-- Defect-dependent placeholder; set from the intended material
	-- quality.

	local enabled = true
	local value = 1.0e21

	return value, enabled
end

function material.ss_srh_sigma_n(state)
	-- Electron capture cross section
	-- Units: m^2
	--
	-- Defect-dependent placeholder; set from measurement.

	local enabled = true
	local value = 1.0e-19

	return value, enabled
end

function material.ss_srh_sigma_p(state)
	-- Hole capture cross section
	-- Units: m^2
	--
	-- Defect-dependent placeholder; set from measurement.

	local enabled = true
	local value = 1.0e-19

	return value, enabled
end

function material.thermal_kl(state)
	-- Thermal conductivity
	-- Units: W m^-1 K^-1
	-- Refs: [2]
	--
	-- ~4.5 W/m/K at x = 0.30 - LOW, from strong mass-disorder phonon
	-- scattering in this quaternary (well below InP's ~68 or InAs's ~27
	-- W/m/K). Weakly dependent in the alloy regime; (300/T)^0.4 approximate.
	-- This low kappa contributes to self-heating in InP-based lasers.

	local enabled = true
	local T = state.T
	local value = 4.5*(300.0/T)^0.4

	return value, enabled
end

function material.heat_capacity(state)
	-- Specific heat capacity
	-- Units: J kg^-1 K^-1
	-- Refs: [3]
	--
	-- ~320 J/kg/K near 300 K (interpolated across the constituents).

	local enabled = true
	local value = 320.0

	return value, enabled
end

function material.density(state)
	-- Mass density
	-- Units: kg m^-3
	-- Refs: [3]
	--
	-- ~5300 kg/m^3 at x = 0.30 (InGaAs ~5500 -> AlInAs ~4650 kg/m^3).

	local enabled = true
	local value = 5300.0

	return value, enabled
end

function material.lattice_constant(state)
	-- Cubic lattice constant
	-- Units: m
	-- Refs: [1],[3]
	--
	-- FIXED at the InP match, a = 5.8697 A, INDEPENDENT of x (Al substitutes
	-- for Ga at constant lattice constant along the InP-matched line).
	-- Linear thermal expansion ~4.6e-6 /K (InP-like).

	local enabled = true
	local T = state.T
	local a300 = 5.8697e-10
	local expansion = 4.6e-6
	local value = a300*(1.0 + expansion*(T - 300.0))

	return value, enabled
end

function material.thermal_tau_e(state)
	-- Electron energy relaxation time towards the lattice temperature
	-- Units: s
	--
	-- Value basis: III-V family estimate
	-- Confidence: Medium
	--
	-- Reference:
	-- https://www.mdpi.com/2673-3978/3/2/16
	--
	-- Comments:
	-- Representative III-V carrier-to-lattice relaxation time. GaAs-like values
	-- are typically sub-ps to ps and field dependent.

	local enabled = true
	local value = 5.000000e-13

	return value, enabled
end

function material.thermal_tau_h(state)
	-- Hole energy relaxation time towards the lattice temperature
	-- Units: s
	--
	-- Value basis: III-V family estimate
	-- Confidence: Medium
	--
	-- Reference:
	-- https://www.mdpi.com/2673-3978/3/2/16
	--
	-- Comments:
	-- Representative III-V carrier-to-lattice relaxation time. GaAs-like values
	-- are typically sub-ps to ps and field dependent.

	local enabled = true
	local value = 5.000000e-13

	return value, enabled
end

function material.delta_so(state)
	-- Spin-orbit splitting energy (Delta_SO)
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*0.28 + ((1.0-x)*y)*0.341 + ((1.0-y))*0.39

	return value, enabled
end

function material.Ep(state)
	-- Kane energy E_P (optical matrix element parameter)
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*21.1 + ((1.0-x)*y)*28.8 + ((1.0-y))*21.5

	return value, enabled
end

function material.gamma1(state)
	-- Luttinger parameter gamma1
	-- Units: dimensionless
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*3.76 + ((1.0-x)*y)*6.98 + ((1.0-y))*20

	return value, enabled
end

function material.gamma2(state)
	-- Luttinger parameter gamma2
	-- Units: dimensionless
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*0.82 + ((1.0-x)*y)*2.06 + ((1.0-y))*8.5

	return value, enabled
end

function material.gamma3(state)
	-- Luttinger parameter gamma3
	-- Units: dimensionless
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*1.42 + ((1.0-x)*y)*2.93 + ((1.0-y))*9.2

	return value, enabled
end

function material.ac(state)
	-- Conduction-band hydrostatic deformation potential a_c
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- VMR sign convention: interband hydrostatic deformation potential
	-- a_gap = a_c - a_v, with a_c negative and a_v tabulated positive.
	-- Sign preserved from source; no sign flip applied.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*-5.64 + ((1.0-x)*y)*-7.17 + ((1.0-y))*-5.08

	return value, enabled
end

function material.av(state)
	-- Valence-band hydrostatic deformation potential a_v
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- VMR sign convention: a_v tabulated as a POSITIVE number; the
	-- interband hydrostatic deformation potential is a_gap = a_c - a_v.
	-- Sign preserved from source; no sign flip applied.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*2.47 + ((1.0-x)*y)*1.16 + ((1.0-y))*1

	return value, enabled
end

function material.b(state)
	-- Valence-band shear (tetragonal) deformation potential b
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Sign convention as in VMR (b negative). Sign preserved; not flipped.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*-2.3 + ((1.0-x)*y)*-2 + ((1.0-y))*-1.8

	return value, enabled
end

function material.d(state)
	-- Valence-band shear (rhombohedral) deformation potential d
	-- Units: eV
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Sign convention as in VMR (d negative). Sign preserved; not flipped.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = (x*y)*-3.4 + ((1.0-x)*y)*-4.8 + ((1.0-y))*-3.6

	return value, enabled
end

function material.lattice_a(state)
	-- Cubic (zincblende) lattice constant a
	-- Units: m
	--
	-- Reference:
	-- Vegard's law (linear) interpolation of AlAs, GaAs, InAs endpoints,
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Endpoint a(T)=a300+da/dT*(T-300); linear (Vegard) mixing.

	local enabled = true
	local x = state.x
	local y = state.y
	local T = state.T
	local value = ((x*y)*(5.6611 + 2.90e-05*(T-300.0)) + ((1.0-x)*y)*(5.65325 + 3.88e-05*(T-300.0)) + ((1.0-y))*(6.0583 + 2.74e-05*(T-300.0)))*1e-10

	return value, enabled
end

function material.C11(state)
	-- Elastic stiffness constant C11
	-- Units: Pa
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = ((x*y)*125 + ((1.0-x)*y)*122.1 + ((1.0-y))*83.29)*1e9

	return value, enabled
end

function material.C12(state)
	-- Elastic stiffness constant C12
	-- Units: Pa
	--
	-- Reference:
	-- Linear interpolation of binary endpoints AlAs, GaAs, InAs from
	-- Vurgaftman, Meyer, Ram-Mohan, J. Appl. Phys. 89, 5815 (2001).
	--
	-- Note:
	-- Composition: (Al(x)Ga(1-x))(y)In(1-y)As; x=Al fraction of (Al,Ga), y=(Al+Ga) group-III fraction.
	-- Linear interpolation of endpoints (no bowing applied).

	local enabled = true
	local x = state.x
	local y = state.y
	local value = ((x*y)*53.4 + ((1.0-x)*y)*56.6 + ((1.0-y))*45.26)*1e9

	return value, enabled
end

function material.C44(state)
    -- Elastic stiffness constant C44
    -- Units: Pa
    --
    -- No sufficiently reliable value/reference identified.
    -- Disabled rather than estimated.
    --
    -- Notes:
    -- Composition mapping is ambiguous: AlGaInAs is written both as
    -- Al_x Ga_y In_(1-x-y) As and as (Al_x Ga_(1-x))_y In_(1-y) As. The
    -- state.x/state.y convention of this file cannot be established from the
    -- filename alone, so no interpolation is implemented.

    local enabled = false
    local value = 0.0

    return value, enabled
end

function material.phonon_lo_energy(state)
    -- Representative LO phonon energy for polar optical (Frohlich) scattering
    -- Units: eV
    --
    -- No sufficiently reliable value/reference identified.
    -- Disabled rather than estimated.
    --
    -- Notes:
    -- Composition mapping is ambiguous: AlGaInAs is written both as
    -- Al_x Ga_y In_(1-x-y) As and as (Al_x Ga_(1-x))_y In_(1-y) As. The
    -- state.x/state.y convention of this file cannot be established from the
    -- filename alone, so no interpolation is implemented.
    -- In addition the alloy is multi-mode (GaAs-, InAs-, AlAs-like LO) with
    -- no recognised single effective Frohlich mode.

    local enabled = false
    local value = 0.0

    return value, enabled
end

function material.epsilon_static(state)
    -- Static relative dielectric constant (lattice + electronic)
    -- Dimensionless
    --
    -- No sufficiently reliable value/reference identified.
    -- Disabled rather than estimated.
    --
    -- Notes:
    -- Composition mapping is ambiguous: AlGaInAs is written both as
    -- Al_x Ga_y In_(1-x-y) As and as (Al_x Ga_(1-x))_y In_(1-y) As. The
    -- state.x/state.y convention of this file cannot be established from the
    -- filename alone, so no interpolation is implemented.

    local enabled = false
    local value = 0.0

    return value, enabled
end

function material.epsilon_inf(state)
    -- High-frequency (electronic) relative dielectric constant
    -- Dimensionless
    --
    -- No sufficiently reliable value/reference identified.
    -- Disabled rather than estimated.
    --
    -- Notes:
    -- Composition mapping is ambiguous: AlGaInAs is written both as
    -- Al_x Ga_y In_(1-x-y) As and as (Al_x Ga_(1-x))_y In_(1-y) As. The
    -- state.x/state.y convention of this file cannot be established from the
    -- filename alone, so no interpolation is implemented.

    local enabled = false
    local value = 0.0

    return value, enabled
end

function material.e14(state)
    -- Zincblende piezoelectric stress coefficient e14
    -- Units: C m^-2
    --
    -- No sufficiently reliable value/reference identified.
    -- Disabled rather than estimated.
    --
    -- Notes:
    -- Composition mapping is ambiguous: AlGaInAs is written both as
    -- Al_x Ga_y In_(1-x-y) As and as (Al_x Ga_(1-x))_y In_(1-y) As. The
    -- state.x/state.y convention of this file cannot be established from the
    -- filename alone, so no interpolation is implemented.

    local enabled = false
    local value = 0.0

    return value, enabled
end

function material.print()
	local state = {
		T = 300.0,
		x = 0.0,
		y = 0.0,
		z = 0.0,
		photon_density = 0.0,
	}

	print(string.format("Material:               %s", material.name()))
	print(string.format("Description:            %s", material.description()))
	print(string.format("Formula:                %s", material.formula()))
	print(string.format("Temperature:            %.2f K", state.T))
	print(string.format("Position:               %.6e, %.6e, %.6e m", state.x, state.y, state.z))
	print(string.format("Photon density:         %.6e m^-3", state.photon_density))

	print(string.format("Band gap:               %.6f eV", material.Eg(state)))
	print(string.format("Electron affinity:      %.6f eV", material.Xi(state)))
	print(string.format("Electron mobility:      %.6e m^2/V/s", material.mu_e(state)))
	print(string.format("Hole mobility:          %.6e m^2/V/s", material.mu_h(state)))
	print(string.format("Nc:                     %.6e m^-3", material.Nc(state)))
	print(string.format("Nv:                     %.6e m^-3", material.Nv(state)))
	print(string.format("Relative permittivity:  %.6f", material.epsilonr(state)))

	print(string.format("Radiative coeff.:       %.6e m^3/s", material.free_to_free_recombination(state)))
	print(string.format("Electron Auger coeff.:  %.6e m^6/s", material.auger_Cn(state)))
	print(string.format("Hole Auger coeff.:      %.6e m^6/s", material.auger_Cp(state)))

	print(string.format("SRH trap energy:        %.6f eV", material.ss_srh_trap_energy(state)))
	print(string.format("SRH trap density:       %.6e m^-3", material.ss_srh_Nt(state)))
	print(string.format("SRH sigma n:            %.6e m^2", material.ss_srh_sigma_n(state)))
	print(string.format("SRH sigma p:            %.6e m^2", material.ss_srh_sigma_p(state)))

	print(string.format("Electron energy relax.:  %.6e s", material.thermal_tau_e(state)))
	print(string.format("Hole energy relax.:      %.6e s", material.thermal_tau_h(state)))

	print(string.format("Thermal conductivity:   %.6e W/m/K", material.thermal_kl(state)))
	print(string.format("Heat capacity:          %.6e J/kg/K", material.heat_capacity(state)))
	print(string.format("Mass density:           %.6e kg/m^3", material.density(state)))
end

return material

-- ============================================================================
-- Copyright (C) 2026 The OghmaNano Project
-- All rights reserved.
--
-- This file is part of the OghmaNano Materials Model Library.
--
-- Website:
-- https://www.oghma-nano.com
--
-- Documentation and accuracy statement:
-- https://www.oghma-nano.com/manual/material-scripts.html
--
-- These material models are provided to support scientific research and
-- semiconductor device simulation. If you find them useful, please cite
-- OghmaNano where appropriate. Please do not redistribute these files or
-- incorporate them into other software or databases without permission.
-- ============================================================================