Chlorine Doped n-Type CdTe Solar Cells

Investigation of Sub‐Bandgap Emission and Unexpected n‐Type Behavior in Undoped Polycrystalline CdSexTe1‐x

“…If a high density of anion vacancies are generated dur-ing the CdCl 2 anneal, Cd-rich conditions would be created and the CdSe x Te 1-x film may be easier to dope with Cl, as demonstrated in CdTe single crystal studies. [19,21,49] Of course, defect complexes may also form, such as the chlorine "A-center" (V Cd -Cl Te ), which acts as a shallow donor when in C S symmetry. [49] Oxygen complexes such as the oxygen "A-center" (V Cd -O Te ) or Te Cd -O Te may also form, but these defects may tend to be shallow acceptors.…”

“…Specifically, anion vacancies may form more readily in CdSe x Te 1-x than CdTe, [17] which could then be filled with chlorine to form Cl Te , a known shallow donor defect in CdTe. [19][20][21] Unintentional n-type behavior in CdSe x Te 1-x at the front of devices could result in losses from buried junction effects, compensation, low activation, and so on.…”