Abstract: A capacitor comprises a stack of layers made of a semiconductor material having a band gap energy greater than 2.3 eV, the stack of layers comprising: an electrically insulating intermediate layer having a resistivity greater than 10 kohm·cm and comprising n- or p-type deep dopants producing energy levels more than 0.4 eV from the conduction band or the valence band of the semiconductor material, two contact layers having a resistivity less than or equal to 10 kohm·cm and comprising dopants of a type opposite to that of the deep dopants of the intermediate layer, the two contact layers being arranged on either side of the intermediate layer to form two pn junctions.