In order to fabricate integrated imaging and particle sensors a hydrogenated amorphous silicon (a-Si:H) p+-i-n+ photodiode technology has been developed, optimized and modelled. The realisation of a one-dimensional model of this by Chatterjee has given us a precious modelling reference. In this paper we propose a bi-dimensional model realized in finite elements approach with Atlas-Silvaco Software of particle sensor achieved by a 4 µm p+-i-n+ amorphous silicone photodiode. We will validate it by comparison with the above-mentioned one-dimensional model. The interest of the second dimension lies not only in the calibration of different structures but also in the influence between neighbouring pixels of the sensor and how this will affect their sensibility. Thus a three pixel bi-dimensional structure has been realized. The leakage and crosstalk currents between two neighbouring pixels have been studied and characterized using a uniform AM1.5 light source.