Semiconductors are the core of modern electronics1. Because of their brittleness, semiconductors are usually processed by the complicated techniques of sputtering or deposition2–4, instead of the effective and versatile metalworking methods like rolling, extrusion and pressing used with metals5. Here we show that brittle semiconductors can be plastically manufactured with an extensibility as large as ~3,000% using warm metalworking, that is, plastic manufacturing at slightly elevated temperatures (empirically below 500 K). Many bulk brittle semiconductors, such as Cu2Se, Ag2Se and Bi90Sb10, can be processed like metals below 400–500 K into free-standing, large and high-quality films with a thickness from the macro-scale to the micrometre scale. A model based on temperature-dependent collective atomic displacement and thermal vibration is proposed to explain the superior plasticity. The warm-metalworked films can retain the excellent and tunable physical properties of the bulk versions, such as a high carrier mobility up to ~5,000 cm2 V−1 s−1 and tunable electrical conductivities over six orders of magnitude by adjusting the chemical composition. A case study in film thermoelectric devices demonstrates ultra-high normalized output power densities of 43–54 μW cm−2 K−2. This work suggests that brittle semiconductors can be manufactured by warm metalworking for applications in various electronics.
