Analytical modelling for p-i-n structured semiconductor devices

Abstract

An analytical model for illuminated p-i-n structures such as Solar Cells and related devices has been developed. Starting from the semiconductor equations in their most general form, and introducing assumptions for the recombination and electrical field functions, it is aimed at modelling not only the collection of photogenerated carriers but all transport mechanisms such as carrier drift and diffusion. Using this model, the behaviour of thin film cells which is observed in operation is described in detail. This includes the dependencies of I/V curves on temperature, insolation and spectral effects, and electronic materials properties. The modeling of recombination effects results in a voltage dependent photocurrent where the carrier collection efficiency depends on the bias voltage. This model allows for relatively fast calculation of I/V curves as it is computationally less extensive than full device numerical simulations. Therefore it may be applicable for compact models i.e. in solar cell performance modelling.