A Novel Analytical Approach to the Solar Cell Junction Physical Parameters Identification

Studies are being actively conducted to improve the efficiency and performances of photovoltaic and thermo-photovoltaic systems and cells. To ameliorate designs and performances of these systems, where semiconducting junctions are generally used, it is very necessary to understand the electrical properties of these devices and conduction processes occurring across the interface of the structure. It is well known that operation and performances of photovoltaic components are strongly related to what is called dark current. Knowing the origin of this current allows improving the structure's configuration of a device, for example by adjusting the semiconducting layers thicknesses and their doping concentrations. However, solar cell models have a non-linear form with numerous parameters. To obtain accurate parameter values, assumptions that differ from real operating conditions must be made to avoid computational complexity. In this work, we proposed a new analytical approach to analyze the experimental current density-voltage of the solar cell models, and to the numerically extraction of the intrinsic solar cells parameters (i.e., the ideality coefficient and the series resistance). Our approach gives very good results. Moreover it is very simple to use and presents the advantage of being independent of the voltage step in contrary to the derivative and to the integral. We have then applied our technique to a whole solar cell current density-voltage curve and the results are very good.