Screen printed contacts formation by rapid thermal annealing in multicrystalline silicon solar cells

The aim of the present work is to optimize the rapid thermal annealing (RTA) parameters in both front and back screen printed contacts realization on Polix p-type multicrystalline silicon phosphorus diffused solar cells. The RTA treatments were carried out at various temperatures from 500 to 750°C and annealing time ranging from 10 to 120 s in an Ar ambiance. The contacts parameters are obtained according to transmission line model measurements. A good RTA cycle is obtained with a temperature plateau of 650°C-700°C and an annealing time of 120 s. The cooling down rate seems a main parameter. The influence of the cooling down rate on the contact resistance is more important in the case of the rear contact. The specific contact resistance is more sensitive to cooling down rate and a value of -10°C/s seems to be the best rate for both front and back contacts