Heterojunction interface double layer and consequences for photovoltaic cells, specifically CdzZn1–zS/Cu2S

It is shown that an interface dislocation field at a heterojunction with substantial lattice mismatch needs charge compensation which can cause a double layer producing a potential spike at the interface. Tunneling through such a spike reduces the current through the interface. Reasonable agreement between theory and experiment is obtained for CdzZn1–zS/Cu2S photovoltaic cells.