High-Efficiency InN-Based Quantum Dot Solar Cells for Defense Applications

Nitride semiconductors possess a number of unique material properties applicable to energy harvesting photovoltaic devices, including a large range of energy gaps, superior radiation resistance, and tolerance to high temperatures. We present here our experimental results related to the self-assembled InN quantum dots formed on Si substrates. We have been successful at synthesizing InN quantum dots using the metal-organic chemical vapor deposition (MOCVD) process. We demonstrate the synthesis of a high density of InN dots exhibiting excellent structural and optical properties. An unprecedented range of absorption energies, ranging from the infrared to the ultraviolet, can be obtained by embedding InN-based quantum dots in a wide band gap GaN barrier. The combination of energy-gaps accessible to III-V nitride materials may be used to reap the benefits of advance quantum dot device concepts involving hot carrier effects or multiple carrier generation processes.