Performance predictions and optimisation strategies in current nanotechnology-based photovoltaic (PV) require simulation tools that can efficiently and accurately compute optical and electrical performance parameters of intricate 3D geometrical structures. Due to the complexity of each type of simulation it is often the case that a single package excels in either optical or electrical modelling, and the other remains a bottleneck. In this work, an efficient tool flow is described in order to combine the highly effective optical simulator Lumerical with the excellent fabrication and electrical simulation capability of Sentaurus. Interfacing between the two packages is achieved through tool command language and Matlab, offering a fast and accurate electro-optical characteristics of nano-structured PV devices.