We have investigated the binding energy properties of a cylindrical quantum dot (CQD) system layered as GaAs/AlGaAs under external electric fields. In our numerical calculations, we considered both on- and off-center impurity cases using the effective mass approximation. The eigenvalues and corresponding eigenfunctions of the system are obtained using a three-dimensional finite difference approach. It is found that the ground-state binding energy is significantly affected by the CQD dimensions (radius and height), impurity position, and the strength and direction of the external electric field. Additionally, the electron probability distributions are examined to provide deeper insight into the physical reasons underlying the behavior of the binding energy. These findings enhance our understanding of the tunable properties of CQDs, which may be useful in the design of optoelectronic and quantum devices.