Solar cells, Cadmium telluride, Mobilities
Condensed Matter Physics
We report electron and hole drift mobilities in thin film polycrystalline CdTe solar cells based on photocarrier time-of-flight measurements. For a deposition process similar to that used for high-efficiency cells, the electron drift mobilities are in the range of 10–100 cm2/Vs, and holes are in the range of 1–10 cm2/Vs. The electron drift mobilities are about a thousand times smaller than those measured in single crystal CdTe with time-of-flight; the hole mobilities are about ten times smaller. Cells were examined before and after a vapor phase treatment with CdCl2; treatment had little effect on the hole drift mobility, but decreased the electron mobility. We are able to exclude bandtail trapping and dispersion as a mechanism for the small drift mobilities in thin film CdTe, but the actual mechanism reducing the mobilities from the single crystal values is not known.
Long, Qi; Dinca, Steluta A.; Schiff, Eric A.; Yu, Ming; and Theil, Jeremy, "Electron and hole drift mobility measurements on thin film CdTe solar cells" (2014). Physics. 516.
APPLIED PHYSICS LETTERS 105, 042106 (2014)