Investigation of InAs/GaAs1−xSbx quantum dots for applications in intermediate band solar cells

摘要

The reduction of the effective band gap and the valence band offset are observed by increasing the Sb composition in GaAs1-xSbx matrix encapsulating InAs quantum dots (QDs). To investigate the potential of the InAs/GaAs1-xSbx system for intermediate band solar cells a p-i-n solar cell with a degenerate valence band is grown. An enhancement in the QDs region with increasing temperature is observed in temperature dependent external quantum efficiency measurements. An “s-shape” behavior of the short circuit current density, JSc, is observed as the temperature increases. Ongoing investigations to illuminate the physical mechanisms contributing to the “s-shape” behavior of Jsc will also be presented.