Hi @zhoude, You can model Schottky contacts at the metal semiconductor interface by setting the “force ohmic” option to false in the properties of the electrical contact.
By default the “force ohmic” option is set to true and the solver adjusts the work function of the metal internally to match with the work function of the semiconductor in contact to form and ohmic contact. However, if you choose to set this to false then the solver will calculate the band bending at the interface depending on the work function of the metal and the semiconductor and therefore you will be able to model the effect of the Schottky contact.
One thing to note here is that the CHARGE solver does not perform a quantum mechanical calculation of the tunneling current at the Schottky barrier but uses an “effective barrier lowering” model to adjust the thermionic current and thereby account for the tunneling current. This approach is only valid as along as the contribution of tunneling current is much smaller compared to the thermionic current. However this assumption should be valid for MSM photodetectors (in my understanding) and therefore you should be able to simulate them with the CHARGE solver.