Provided are selector elements having snapback characteristics and non-volatile memory cells comprising such selector elements. To achieve its snapback characteristic, a selector element may include a dielectric layer comprising an alloy of two or more materials. In the same or other embodiments, the selector element may include a doped electrode, such carbon electrodes doped with silicon, germanium, and/or selenium. Concentrations of different materials forming an alloy may vary throughout the thickness of the dielectric layer. For example, the concentration of the first one alloy material may be higher in the center of the dielectric layer than near the interfaces of the dielectric layer with the electrodes. Some examples of this alloy material include germanium, indium, and aluminum. Examples of other materials in the same alloy include silicon, gallium, arsenic, and antimony. In some embodiments, the alloy is formed by three or more elements, such as indium gallium arsenic.