Organic solar cells are of great interest, due to their relative cheapness and ease of fabrication. Unfortunately the efficiency of the devices is much lower than the alternative inorganic devices. Organic solar cells are made from blends of 2 organic semiconductors, most common is regio-regular polythiothene (RR-P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). This proposal looks to build on previous research, which studied the ALCs of RR-P3HT and PCBM separately. Now we want to study the ALCs of the blended system P3HT:PCBM. The aims are to determine i. how the ALCs change as a function of temperature, ii. whether the magnetic impurities in RR-P3HT make a difference to the ALCs of the blended system and iii. to make sure that both sets of ALC s can be observed as a function of temperature. These measurements need to be understood before studying the system using the laser on HiFi