old_contents: #
  #   Copyright (c) 2015, Scott J Maddox
  #
  #   This file is part of Open Band Parameters Device Simulator (OBPDS).
  #
  #   OBPDS is free software: you can redistribute it and/or modify
  #   it under the terms of the GNU Affero General Public License as published
  #   by the Free Software Foundation, either version 3 of the License, or
  #   (at your option) any later version.
  #
  #   OBPDS is distributed in the hope that it will be useful,
  #   but WITHOUT ANY WARRANTY; without even the implied warranty of
  #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #   GNU Affero General Public License for more details.
  #
  #   You should have received a copy of the GNU Affero General Public License
  #   along with OBPDS.  If not, see <http://www.gnu.org/licenses/>.
  #
  #############################################################################
  
  # Make sure we import the local obpds version
  import os
  import sys
  sys.path.insert(0,
      os.path.abspath(os.path.join(os.path.dirname(__file__), '../..')))
  from obpds import GaAs, cm3, um, Material, Layer, OhmicContact, LayerStructure
  
  # Layers
  p = Layer(1*um, Material(GaAs,  1e17/cm3))
  n = Layer(1*um, Material(GaAs, -1e17/cm3))
  
  # Contacts
  top = OhmicContact()
  bottom = OhmicContact()
  
  # Layer Structure
  ls = LayerStructure([top, p, n, bottom])
  
  # ls.show_composition() # show the composition vs. depth
  # ls.show_doping() # show the doping vs. depth
  # ls.show_flatband() # show the flatband profile vs. depth
  
  # Simulate and show the equilibrium band profile using the default method.
  ls.show_equilibrium()
new_contents: #
  #   Copyright (c) 2015, Scott J Maddox
  #
  #   This file is part of Open Band Parameters Device Simulator (OBPDS).
  #
  #   OBPDS is free software: you can redistribute it and/or modify
  #   it under the terms of the GNU Affero General Public License as published
  #   by the Free Software Foundation, either version 3 of the License, or
  #   (at your option) any later version.
  #
  #   OBPDS is distributed in the hope that it will be useful,
  #   but WITHOUT ANY WARRANTY; without even the implied warranty of
  #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #   GNU Affero General Public License for more details.
  #
  #   You should have received a copy of the GNU Affero General Public License
  #   along with OBPDS.  If not, see <http://www.gnu.org/licenses/>.
  #
  #############################################################################
  
  # Make sure we import the local obpds version
  import os
  import sys
  sys.path.insert(0,
      os.path.abspath(os.path.join(os.path.dirname(__file__), '../..')))
  from obpds import *
  
  # Layers
  p = Layer(1*um, Material(GaAs,  1e17/cm3))
  n = Layer(1*um, Material(GaAs, -1e17/cm3))
  
  # Device
  d = Device(layers=[p,n])
  
  # Simulate and show the equilibrium band profile using the default method.
  d.show_equilibrium()
subject: simplify `examples.pn_diode`