From c6fe6b495c7d10bd6e86f02de6648e62871a3a44 Mon Sep 17 00:00:00 2001 From: Phoebe Pearce Date: Wed, 24 Jul 2024 14:27:09 +1000 Subject: [PATCH] documentation update --- docs/source/Solvers/depletion.rst | 44 +++++++++++++++++++++++++++++++ docs/source/conf.py | 2 +- 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/docs/source/Solvers/depletion.rst b/docs/source/Solvers/depletion.rst index 1c8b8b65..cc02dd01 100755 --- a/docs/source/Solvers/depletion.rst +++ b/docs/source/Solvers/depletion.rst @@ -3,6 +3,50 @@ Depletion approximation - Example: :doc:`Traditional GaInP/InGaAs/Ge solar cell <../Examples/example_3J_with_DA_solver>` +Material and device parameters +--------------------------------- + +The table below lists the device and material parameters required for the depletion approximation solver. It is not +necessary to set all these parameters explicitly, as some can be calculated from other parameters or have default values. +However, there is no reason to assume the default values are reasonable for your material/device! + +========================== ============================ ============================= ========== ======== ============================================= +Parameter Set location Solcore label Units Default Calculable? +========================== ============================ ============================= ========== ======== ============================================= +n-type region SRV ``Junction`` ``sn`` :sup:`[1]` m s-1 0 No +p-type region SRV ``Junction`` ``sp`` :sup:`[1]` m s-1 0 No +Permittivity ``Junction`` or ``material`` ``permittivity`` F m-1 none Yes, from ``relative_permittivity`` :sup:`[2]` +Electron diffusion length p-type ``material`` ``electron_diffusion_length`` m none No +Hole diffusion length or n-type ``material`` ``hole_diffusion_length`` m none No +Electron mobility p-type ``material`` ``electron_mobility`` m2 V-1 s-1 0.94 No :sup:`[3]` +Hole mobility n-type ``material`` ``hole_mobility`` m2 V-1 s-1 0.05 No :sup:`[3]` +Intrinsic carrier density ``material`` ``ni`` m-3 none Yes, from ``Nc``, ``Nv`` and ``band_gap`` :sup:`[4]` +Donor (n-type) density n-type ``material`` ``Nd`` m-3 1 No +Acceptor (p-type) density p-type ``material`` ``Na`` m-3 1 No +Built-in voltage ``Junction`` (optional) ``Vbi`` V none Yes, from ``Nd``, ``Na`` and ``ni`` :sup:`[5]` +Shunt resistance ``Junction`` (optional) ``R_shunt`` Ohm m2 1e14 No :sup:`[6]` +========================== ============================ ============================= ========== ======== ============================================= + +Notes: + +1. The n/p labels for the surface recombination velocities ``sn`` and ``sp`` refer to the region, not the carrier type, + e.g. ``sn`` is the recombination velocity at + the n-type surface, which can be the front or rear surface depending on the cell configuration. +2. ``relative_permittivity`` is a dimensionless quantity: permittivity = vacuum permittivity * relative permittivity +3. If the material is not in the :doc:`mobility model database <../Systems/Materials>`, which calculates the mobility + based on the alloy composition (if applicable), temperature, and doping level, the model will default to calculating + the mobility for GaAs. Thus if you are using a custom material not included in the mobility database, you should set + this explicitly, since there is no reason to assume the GaAs values are reasonable for your material. +4. The intrinsic carrier density ``ni`` can be calculated from the conduction and valence band effective density of states + (``Nc`` and ``Nv`` respectively, units m-3) and ``band_gap`` (SI units used by Solcore: J, NOT eV!). +5. In general, you don't need to set the built-in voltage ``Vbi`` since it is calculated from ``Nd``, ``Na`` and ``ni``, + all of which are already required. +6. An ideal cell has infinitely high shunt resistance (hence the extremely high default value). + + +Background +---------- + The depletion approximation provides an analytical - or semi-analytical - solution to the Poisson-drift-diffusion equations described in the previous section applied to simple PN homojunction solar cells. diff --git a/docs/source/conf.py b/docs/source/conf.py index daee8d00..38efc9e8 100755 --- a/docs/source/conf.py +++ b/docs/source/conf.py @@ -68,7 +68,7 @@ # General information about the project. project = u'Solcore' -copyright = u'2023, Quantum Photovoltaics Group, Imperial College London' +copyright = u'2024, Quantum Photovoltaics Group, Imperial College London' # The version info for the project you're documenting, acts as replacement for # |version| and |release|, also used in various other places throughout the