  A nanostructured thermoelectric device is designed by connecting a
double-barrier resonant tunneling heterostructure to two electron reservoirs.
Based on Landauers equation and Fermi-Dirac statistics, the exact solution of
the heat flow is calculated. The maximum power output and efficiency are
calculated through the optimizations of several key parameters. The optimum
characteristic curve of the performance is obtained. The reasonably working
region of the device is determined, the selection criteria of main parameters
are provided, and the optimum configuration of the device is drawn. Results
show that the heterojunction becomes a perfect energy filter by appropriately
regulating the chemical potentials of electron reservoirs and optimally
choosing the widths of barrier and quantum well and the nanostructured
thermoelectric device with resonance tunneling may obtain simultaneously a
large power output and a high efficiency.
