Low-Temperature Concentrated Light Characterization Applied to Intermediate Band Solar Cells

In this paper, we describe a novel low-temperature concentrated light characterization technique, and we apply it to the study of the so-called intermediate band solar cell (IBSC). This type of cell is characterized by hosting an intermediate band (IB) that is capable of providing both high current and high voltage. In most of its practical implementations, which are carried out by means of quantum dot (QD) structures, the energy band-diagram shows additional confined energy levels. These extra levels are responsible for an increase in the thermalization rate between the IB and the conduction band, which produces the degradation of the open-circuit voltage VOC. The original implementation of a setup that combines concentrated light and low temperature conditions is discussed in this paper. In this context, photogenerated current (IL)-VOC characteristics that are measured on QD-IBSC are presented in order to study their recombination, as well as their VOC recovery.