p-Type Bismuth Antimony Telluride With Ag Nanodot Doping for High-Thermoelectric-Performance Wearable Generators: ZT=1.84 at 340 K and Scalable Tape-Cast Fabrication

This study investigates Ag nanodot-doped p-type Bi0.5Sb1.5Te3 thermoelectric material with peak ZT=1.84 at 340 K for wearable body-heat energy harvesting, with tape-cast thin-film fabrication and generator module demonstration within the context of thermoelectric materials science and wearable electronics, an area of growing scientific importance given its implications for body-heat-powered wearable biosensors, self-powered IoT skin-worn devices, and thermoelectric generator integration in smart textiles. Using spark plasma sintering at 440 C/60 MPa, Seebeck coefficient and electrical conductivity by ZEM-3, thermal conductivity by laser flash analysis, Hall effect for carrier concentration, and 8-leg TEG module fabrication with wrist-worn demonstration at DeltaT=6 K (body-ambient), we examine Ag nanodots acting as phonon scattering centers reducing lattice thermal conductivity 48% below undoped BST while simultaneously tuning Fermi level via hole doping, increasing Seebeck coefficient and power factor; optimal 1.5 mol% Ag achieves trade-off between electrical and thermal transport in 5 Ag doping concentrations (0, 0.5, 1.0, 1.5, 2.5 mol%) with n=3 SPS pellets per composition; 2 tape-cast TEG modules (4 cm x 4 cm, 8 p-n couples each) for wrist-worn body heat test drawn from Pacific Materials Institute SPS facility, ZEM-3 characterization system (ULVAC-RIKO), laser flash thermal diffusivity analyzer (NETZSCH LFA 457), and wrist-worn body heat TEG demonstration at 295 K ambient. Results indicate that optimal 1.5 mol% Ag-BST achieves peak ZT=1.84 at 340 K (Seebeck 248 uV/K, sigma=840 S/cm, kappa=0.48 W/mK); tape-cast TEG module generates 28.4 uW/cm2 at DeltaT=6 K body-ambient; 2.4x higher than undoped BST module (p < 0.001), with ZT=1.84 at 340K; 28.4 uW/cm2 at DT=6K; 2.4x vs. undoped; kappa reduced 48% as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to thermoelectric materials science and wearable electronics and carry actionable implications for the design of programs and policies targeting body-heat-powered wearable biosensors, self-powered IoT skin-worn devices, and thermoelectric generator integration in smart textiles.