In this work, the conformal mapping technique is applied to obtain an analytical closed form solution of the 2D Poisson’s equation for a double-gate Tunnel FET. The generated band profiles are accurate in all regions of device operation. Furthermore, the current levels are estimated by implementing the non-local band-to-band tunneling model from Synopsys Sentaurus TCAD. A good agreement with simulations for varying device parameters is demonstrated and the advantages and limitations of the new modeling approach are investigated and discussed.