Display device

A display device for displaying a pattern, comprising a pixel element having a layered structure comprising three different phase change material layers, wherein each of the three different phase change material layers are switchable between a high extinction coefficient state and a low extinction coefficient state, and wherein two or more of the three different phase change material layers differ from each other only by doping, wherein preferably the doping comprises either or both of oxygen and nitrogen as dopant,

• and wherein at least one phase change material layer is thermally switchable between a stable high extinction coefficient state and a stable low extinction coefficient state, wherein, for the at least one phase change material layer:
• a ratio of a mean average, over the visible spectrum, of the extinction coefficient of the at least one phase change material layer in the stable high extinction coefficient state to a mean average, over the visible spectrum, of the extinction coefficient of the at least one phase change material layer in the stable low extinction coefficient state is greater than 3.0;
• and
• the mean average, over the visible spectrum, of the extinction coefficient of the at least one phase change material layer in the stable high extinction state is less than 1.0.