摘要： Temperature-dependent switching between p- and n-type conduction is a newly observed phenomenon in very a few Ag-based semiconductors, which may promote fascinating applications in modern electronics. Pressure, as an efficient external stimulus that has driven collective phenomena such as spin crossover and Mott transition is also expected to initialize a conduction type switching in transition metal based semiconductors. Herein, we report the observation of a pressure-driven dramatic switching between p- and n-type conduction in chalcopyrite CuFeS2 associated with a structural phase transition. Under compression around 8 GPa, CuFeS2 undergoes a phase transition with symmetry breakdown from space group I-42d to I-4 accompanying with a remarkable volume shrinkage of the FeS4 tetrahedra. A high-to-low spin-crossover of Fe2+ (S = 2 to S = 0) is manifested along with this phase transition. Instead of pressure-driven metallization, a surprising semiconductor-to-semiconductor transition is observed associated with the structural and electronic transformations. Significantly, both photocurrent and Hall coefficient measurements confirm that CuFeS2 undergoes a reversible pressure-driven p-n type conduction switching accompanying with the structural phase transition. The absence of cationic charge transfer between copper and iron during the phase transition is confirmed by both X-ray absorption near-edge spectra (Cu/Fe, K-edge) and total-fluorescence-yield X-ray absorption spectra (Fe, K-edge) results, and the valence distribution maintains Cu2+Fe2+S2 in the high pressure phase. The observation of an abrupt pressure-driven p-n type conduction switching in a transition metal based semiconductor paves the way to novel pressure-responsive switching devices.