Growth and Characterization of Arsenic-Doped CdTe1−xSex Single Crystals Grown by the Cd-Solvent Traveling Heater Method

Abstract

The photovoltaic performance of CdTe solar cells is mainly limited by low doping and short minority carrier lifetime. Group-V element doping and Sealloying have a significant impact on tuning these fundamental CdTe properties. In this paper, we report the growth of p-type As-doped, Cd-rich CdTe 1Àx Se x single crystals using metallic Cd as the solvent in the travelingheater method. The structural and electrical properties of CdTe 1Àx Se x are examined for different Se concentrations. CdTe 1Àx Se x single crystals (0 £ x £ 0.5) with zincblende structure indicate homogeneous composition. The 10 17 cm À3 As-doping activation efficiency can be maintained at close to 50% for x £ 0.2. Se alloying leads to bulk minority carrier lifetime exceeding 30 ns for samples doped near 10 17 cm À3. These results help us to overcome the current roadblocks in device performance.