Calculation of the Shunt Resistance across the Absorber Layer of Hydrogenated Amorphous Silicon Photovoltaic Cells

Abstract

In contrast to the existing conventional models, that describe the shunt resistance of hydrogenated amorphous silicon as a uniform resistance a cross the absorber layer (ilayer), our paper calculates the shunt resistance of a-Si:H PV cells as a function of the location across the i-layer resulting in a more detailed description of the shunt resistance. The photogeneration of the electron-hole pairs depend the photons' wavelength values and the potential across the PV cell. The shunt resistance exists because of the current leakage between the front-and back-contact layers within the i-layer. The electric current of the electrons and holes is calculated, in this paper, by solving the Poisson, continuity, and transport equations at each location within the i-layer for wide range potential values. In this article, the contribution of electrons and holes on the shunt leakage is calculated for each carrier independently by separating the current density/voltage (J/V) curves of the electrons and of the holes at each location within the i-layer. This work proves that the effective value of the location-dependent shunt resistances due to the electrons and holes equals the effective shunt resistance of the PV cell calculated from the total J/V.