Activation of CdTe solar cells using molecular chlorine

There has been renewed interest in developing alternatives to CdCl2 activation, a critical but expensive step in CdTe manufacturing. A common element among the alternative agents that have been explored is chlorine, which facilitates recrystallization, passivates grain boundaries, and leads to enhanced efficiency. In this paper we present an evaluation of molecular chlorine (Ch) for CdTe activation. The broad process space was first screened by evaluating the change in the (111) texture coefficient. It is shown that recrystallization occurs quite quickly (~1 minute), and the required concentration of Cl2 is quite low (<;100 ppm). Devices fabricated at promising conditions displayed good rectification with device efficiency's >11%.