Si thin films, grown using ion-beam-assisted deposition of buffer layers on polycrystalline metal-alloy tapes (see Figure), show out-of-plane and in-plane mosaic spreads of 0.8 and 1.3, respectively, and a room-temperature Hall mobility of 89 cm(2) V-1 S-1 for a doping concentration of 4.4 x 10(16) cm(3). These results provide proof-of-concept for a promising materials technology that does not require lattice-matched, single-crystal substrates for deposition of well-oriented, high-carrier-mobility semiconductor thin films.