A broadband multi-purpose optical device includes a semiconductor layer having a light absorption characteristic, a first active layer having a light absorption band different from a light absorption band of the semiconductor layer, a first two-dimensional (2D) material layer adjacent to the first active layer, and a first interfacial layer configured to control a pinning potential of the semiconductor layer and the first active layer. The broadband multi-purpose optical device may further include at least one second active layer, and may include a tandem structure that further includes at least one second 2D material layer. The first active layer and the second active layer may have different light absorption bands. The broadband multi-purpose optical device may further include a second interfacial layer adjacent to the first 2D material layer.