Fig. 2: Ag- or Cu-containing Bi-Sb-Te films: surface morphology, elemental composition, and doping mechanism.
From: Cu- or Ag-containing Bi-Sb-Te for in-line roll-to-roll patterned thin-film thermoelectrics
a AFM images of evaporated-sputtered films with varying concentrations of metal (scale bar = 100 nm). b Surface root mean square roughness - RMSR (Data are presented as mean ± standard deviation from measurements at nine locations on three identical samples). c Elemental composition from EDX-SEM of Bi-Sb-Te composite films (Data are presented as mean ± standard deviation from measurements at eight locations on three identical samples). d Electron shells of these elements with valance electrons. e Interstitial & substitutional doping/alloying, including a visualization of the crystal structure and a band diagram showing anticipated acceptor/donor levels. Blue spheres represent the substitutional or interstitial atoms within the host lattice (grey spheres). Acceptor levels introduce more ‘+’ (holes) into the valence band, while donor levels contribute more ‘-’ (electrons) to the conduction band. The crystal structure models are generated in VESTA using the pure Bi-Sb-Te source data (ICSD: 147547).
