Frequency conversion in a-GaN/AlGaN Bragg-confined structures for applications for solar cells

• Main Authors: Čičić Slobodan D., Radovanović Jelena V., Milanović Vitomir B.
• Format: Article
• Language: English
• Published: Savez inženjera i tehničara Srbije 2014-01-01
• Series: Tehnika
• Subjects: Semiconductor quantum well; Bragg-confined structures; Nonlinear susceptibility
• Online Access: http://scindeks-clanci.ceon.rs/data/pdf/0040-2176/2014/0040-21761403377C.pdf

Solar cells are unable to absorb photons with energies lower than the constituent material's band-gap, which eliminates a significant part of the spectrum. The efficiency of the process may be increased by converting low-energy photon pairs, via nonlinear optical effects, into photons optimal for the solar cell. The converter structures consist of GaN/AlGaN super lattice series perturbed by asymmetric quantum wells which form the Bragg confined structures (BSCs). BCSs support additional bound electron states in the super lattice minigaps, including states above the barrier. Parameters of the structure are optimized for each photon pair, by using the genetic algorithm, to obtain a continual converter.