It is widely known that photoluminescence (PL) and infrared (IR) spectroscopies are among the experimental tools extensively used in the last decades for the study of impurities and defects in silicon for both microelectronic and photovoltaic applications. This review paper reports the main historical achievements and recent developments obtained in this field by PL and IR, paying particular attention to the most useful data for the study of defects in silicon for photovoltaic applications. (C) 2014 Elsevier B.V. All rights reserved.