Schottky and ohmic contact

[rajxabc]

impurity density, how does it work ?
Suppose from [-0.005 - 0.005]x is p-CdTe, and at -0.005 is Al contact

Question1: why impurity dose not start at x = -0.005
Question2: Al is metal contact p-CdTe is semiconductor, will it not be sufficient for Schottky ?

Question2: Can you please give simplest example of [metal]{schottky}[p-semiconductor]{ohmic}[metal] structure

Thanks

T = Float32
sim = Simulation{Float32}(SSD_examples[:InfiniteParallelPlateCapacitor])

struct PNJunctionImpurityDensity{T} <: SolidStateDetectors.AbstractImpurityDensity{T}
    p_type_density::T
    n_type_density::T
end

function SolidStateDetectors.get_impurity_density(
    cdm::PNJunctionImpurityDensity{T},
    pt::SolidStateDetectors.AbstractCoordinatePoint{T}
)::T where {T}
    cpt = CartesianPoint(pt)
    x = cpt[1] # In this example, we only need the `x` coordinate of the point.
    #if x > 0
    if x > -0.005
        -cdm.p_type_density # p-type region -> electrons are fixed -> negative charge --10^14
    else
        cdm.n_type_density  # n-type region -> holes are fixed -> positive charge --NONE
    end
end

pn_junction_impurity_density = PNJunctionImpurityDensity{Float32}(1.0e14, 0)  

sim.detector = SolidStateDetector(sim.detector, pn_junction_impurity_density);
calculate_electric_potential!(
    sim,
    convergence_limit = 1e-6,
    max_tick_distance = (0.002, 1, 1) .* u"cm",
    min_tick_distance = (1e-7, 1, 1) .* u"m",
    refinement_limits = [0.005, 0.001],
    depletion_handling = true
)
calculate_electric_field!(sim)

display(

    begin
plot(
    plot(sim.electric_potential, y = 0),
    plot(sim.imp_scale, y = 0),
    plot(sim.point_types, y = 0),
    layout = (3, 1),
    aspect_ratio = :none,
    size = (800, 800)
)
    end
)

[fhagemann]

This looks good, in principle.
Code-wise, the only thing you could do is to use a ConstantImpurityDensity, if you just have a p-type bulk.
This is because they impurity density is only applied to the semiconductor, not the contacts or surroundings:

using SolidStateDetectors
using Unitful
using Plots

T = Float32
sim = Simulation{T}(SSD_examples[:InfiniteParallelPlateCapacitor])
sim.detector = SolidStateDetector(sim.detector, SolidStateDetectors.ConstantImpurityDensity{T}(-1e14))

calculate_electric_potential!(
    sim,
    convergence_limit = 1e-6,
    max_tick_distance = (0.002, 1, 1) .* u"cm",
    min_tick_distance = (1e-7, 1, 1) .* u"m",
    refinement_limits = [0.005, 0.001],
    depletion_handling = true
)
# calculate_electric_field!(sim)
plot(
    plot(sim.electric_potential, y = 0),
    plot(sim.imp_scale, y = 0),
    plot(sim.point_types, y = 0),
    layout = (3, 1),
    aspect_ratio = :none,
    size = (800, 800)
)

One thing that might explain why you are not seeing any depletion:
Is your impurity density 10^14 m^-3 = 10^-8 cm^-3 or 10^14 cm^-3 = 10^20 m^-3?
Unitless quantities will always be parsed as if they had SI-units, so here it would be 10^14 m^-3.

If I assume 10^14 cm^-3 = 10^20 m^-3, I can see some depletion behavior:

using SolidStateDetectors
using Unitful
using Plots

T = Float32
sim = Simulation{T}(SSD_examples[:InfiniteParallelPlateCapacitor])
sim.detector = SolidStateDetector(sim.detector, SolidStateDetectors.ConstantImpurityDensity{T}(-1e20))

calculate_electric_potential!(
    sim,
    convergence_limit = 1e-6,
    max_tick_distance = (0.002, 1, 1) .* u"cm",
    min_tick_distance = (1e-7, 1, 1) .* u"m",
    refinement_limits = [0.005, 0.001],
    depletion_handling = true
)
# calculate_electric_field!(sim)
plot(
    plot(sim.electric_potential, y = 0),
    plot(sim.imp_scale, y = 0),
    plot(sim.point_types, y = 0),
    layout = (3, 1),
    aspect_ratio = :none,
    size = (800, 800)
)

However, the depletion propagates so slowly that I also believe that this value is way too high.

For -1e16 = 10^16 cm^-3 = 10^10 m^-3, I get something that depletes within something like 600V:

using SolidStateDetectors
using Unitful
using Plots

T = Float32
sim = Simulation{T}(SSD_examples[:InfiniteParallelPlateCapacitor])
sim.detector = SolidStateDetector(sim.detector, SolidStateDetectors.ConstantImpurityDensity{T}(-1e16))
    
a = @animate for V in (20:20:600)u"V"
    print(V)
    sim.detector = SolidStateDetector(sim.detector, contact_id = 1, contact_potential = V)

    calculate_electric_potential!(
        sim,
        convergence_limit = 1e-6,
        max_tick_distance = (0.02, 1, 1) .* u"cm",
        min_tick_distance = (1e-6, 1, 1) .* u"m",
        refinement_limits = [0.005],
        depletion_handling = true,
        verbose = false
    )
    plot(
        plot(sim.electric_potential, y = 0, title = V),
        plot(sim.imp_scale, y = 0),
        plot(sim.point_types, y = 0),
        layout = (3, 1),
        aspect_ratio = :none,
        size = (800, 800),
    )
end

gif(a, fps = 5)

[rajxabc]

Thanks :o),
This worked for my problem

[fhagemann]

So, to specifically answer your questions:
1.) I am not sure what you mean. According to my gif, the semiconductor starts depleting from x = -0.005.
2.) The metal contacts and p-CdTe should in principle be enough. You might wanna check the dimensions of the diode (1cm) and the impurity density level. Both of them affect how much you will see depletion.
3.) The example you provided should be fine to simulate a [metal]{schottky}[p-semiconductor]{ohmic}[metal] structure