High-Efficiency, High-Power Density III-V Multijunction Solar Cells on Si and Hybridsil

This DOD Phase I STTR program would develop III-V multijunction based solar cells, using Virginia Tech"s InGaP/GaAs/InGaAs multijunction cells technique in combination with NanoSonic"s pioneering Hybridsil antireflection copolymer nanocomposite materials, which afford high levels of antireflection, temperature and abrasion resistance, impact durability and hydrophobicity (self cleaning). Such an approach to form flexible PV materials and devices offers advantages over dye-sensitized solar cells (DSSC) and hydrogenated amorphous silicon based flexible PV devices, in that much higher energy efficiency can be obtained on flexible substrates with large area manufacturing and processing. The central theme of our proposal is to demonstrate heterogeneously integrated high efficiency III-V multijunction solar cells on cheaper, larger diameter and readily available Si substrate as well as solar cells through epitaxial release from Si. The released multijunction structures will be transferred to NanoSonic"s highly transparent, super lightweight and mechanically robust Hybridsil materials to be integrated into flexible PV devices. NanoSonic"s Hybridsil composites will be used not only as the substrates but also the antireflection coatings to enhance the device efficiency.