Unusual impact of electron-phonon scattering in Si nanowire field-effect-transistors: A possible route for energy harvesting

•A transport model for Si nanowire field-effect-transistors has been developed.•Simultaneous impact of e-ph scattering and effective mass mismatch between nanowire channel and source/drain is investigated.•The device current is observed to enhance anomalously due to such scattering above a certain S/D doping level.•The use of high-k gate oxides for such purpose can enhance the scattering power gain.•Novel path for phonon energy harvesting in nanotechnology is suggested.

In the current work, the impact of electron-phonon scattering phenomena on the transport behaviour of silicon nanowire field-effect-transistors with sub-mean free path channel length has been investigated by developing a theoretical model that incorporates the responses of carrier effective mass mismatch between the channel and source/drain. For this purpose, a set of relevant quantum field equations has been solved by non-equilibrium Green's function formalism. The obtained device current for a particular set of biases is found to decrease due to phonon scattering below a certain doping level of source/drain, above which it is observed to enhance anomalously. Analyses of the quantified scattering lifetime and power dissipation at various confinement modes of the device indicates that such unusual enhancement of current is originated from the power served by phonons instead of associated decay processes. The power generation has been observed to improve by using high-k materials as gate insulator. Such results may contribute significantly to the future nano-electronic applications for energy harvesting.

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