Multistage interband cascade photovoltaic devices with a bandgap of 0.23 eV operating above room temperature

• DOI: 10.1007/s11434-014-0144-6
• Publication Date: 2014-01-28T02:58:12Z
• Authors: Hao Ye; Hossein Lotfi; Lu Li; Robert T. Hinkey; Rui Q. Yang; Lin Lei; Joel C. Keay; Matthew B. Johnson; Tetsuya D. Mıshıma; Michael B. Santos
• Keywords: Thermophotovoltaic; Open-circuit voltage

Interband cascade (IC) photovoltaic (PV) device structures, consisting of multiple discrete InAs/GaSb superlattice absorbers sandwiched between electron and hole barriers, were grown by molecular beam epitaxy. Details of the molecular beam epitaxy growth and material characterization of the structures are presented. The discrete absorber architecture enables certain advantages, such as high open-circuit voltage, high collection efficiency, high operating temperature, and smooth integration of cascade stages with different bandgaps. The two- and three-stage ICPV devices presented in this article operate at room temperature with substantial open-circuit voltages at a cutoff wavelength of 5.3 μm (corresponding to a bandgap of 0.23 eV), the longest ever reported for room temperature PV devices. The device characteristics indicate a high level of current matching and demonstrate the advantages of the interband cascade approach in thermophotovoltaic cell design.