Ultra-flexible organic-inorganic hybrid Bi2Te3 thin films for thermoelectric generators

Achieving high thermoelectric (TE) performance and flexibility is essential for wearable electronics. Here, an organic-inorganic hybrid strategy incorporating methylammonium lead iodide (MAPbI(3)) into Bi2Te3 thin films enhances both TE and mechanical properties. Pb/I incorporate into Bi2Te3 lattice, improving electrical conductivity via enhanced carrier transport and moderate doping effects. Meanwhile, amorphous phases derived from MA-related species strengthen phonon scattering, reducing kappa(l)+kappa(bi) from 1.1 Wm(-1)K(-1) to 0.1 Wm(-1)K(-1). As a result, the zT value improves from 0.08 to 0.94 at 250 degrees C. Moreover, the amorphization effect induced by the amorphous inclusions enhances flexibility by reducing the Young's modulus, yielding a resistance change of <7 % (Delta R/R-0) after bending. Specifically, the 0.6 wt. % sample exhibits only a 2.5 % resistance change after 5000 bending cycles. Finally, a flexible TE generator fabricated with hybrid films and Ag electrodes delivers a high output power of 35.3 nW under a 20 degrees C temperature gradient, highlighting the potential of this hybrid approach for wearable electronics.