Abstract: A method of manufacturing an electrically actuable switch and comprising: depositing a first electrode on a surface; depositing an active layer or layers on top of said first electrode; and depositing a second electrode on top of said active layer(s), wherein said step of depositing an active layer or layers is performed in an atmosphere into which a reactive gas is introduced, the partial pressure of the reactive gas being varied during the process so as to introduce dopants into the active layer in a concentration which varies across the active layer.