While Dr. Nagaoka was a visiting postdoc (he is now an assistant professor at University of Miyazaki in Japan), Prof. Scarpulla and he pioneered the growth of CdTe single crystals doped with P, As, and Sb by growing by the travelling heater method (THM) using Cd rather than the typical Te as the solvent. These crystals have exhibited some of the highest hole densities and minority carrier lifetimes in p-type CdTe, which are the critical parameters for increasing the efficiency of CdTe thin film solar cells. This collaboration is ongoing and keeps producing remarkable results!