Triboelectric Nanogenerator‐Enabled Constant‐Charge Spectroscopy of Energy–Space Trap States in Polymer Dielectrics

Abstract

Trap states govern charge transport, accumulation, and local‐field distortion in polymer dielectrics, yet quantitative mapping of their energy, density, and spatial distribution remains challenging. Here, triboelectric nanogenerator (TENG)‐enabled constant‐charge spectroscopy based on dielectric‐barrier discharge (DBD) is developed to resolve trap energy, density, and spatial distribution. The rotary TENG supplies kilovolt excitation at high impedance with a stable transferred charge of ∼ 262 nC per cycle, while needle geometry and discharge gap balance stable DBD formation with detrapping‐signal visibility. A coupled carrier–field model separates the plasma‐driven background, enabling reconstruction of trap energy and density. Corona treatment induces material‐specific redistribution: polytetrafluoroethylene (PTFE) develops an additional trap population and spectral broadening, whereas polyamide (PA) retains a multilevel distribution with marked enrichment of lower‐energy states. Comparison with thermally stimulated depolarization current measurements gives relative deviations of 7.18%–8.23%. Density functional theory calculations show that representative PTFE and PA defects generate localized unoccupied states at comparable sub‐eV scales through distinct electronic reorganizations, rationalizing their different spectral evolution. Measurements at 36 positions further reveal a treated PA region where trap‐energy shallowing coincides with increased trap density. TENG‐enabled constant‐charge spectroscopy therefore resolves material‐specific trap redistribution across both energy and space.