In a new EFRC-supported publication titled “III-nitride core-shell nanowire arrayed solar cells” published in Nanotechnology, EFRC scientists Jonathan J. Wierer, Qiming Li, Daniel D. Koleske, and George T. Wang and Sandia National Laboratories scientist Stephen R. Lee present their work on a unique hybrid nanowire structure. The article established that this structure served a dual purpose, both in improving power conversion efficiency as well as being beneficial for other III-nitride devices such as light-emitting diodes (LEDs).
Abstract: A solar cell based on a hybrid nanowire–film architecture consisting of a vertically aligned array of InGaN/GaN multi-quantum well core–shell nanowires which are electrically connected by a coalesced p-InGaN canopy layer is demonstrated. This unique hybrid structure allows for standard planar device processing, solving a key challenge with nanowire device integration, while enabling various advantages by the nanowire absorbing region such as higher indium composition InGaN layers by elastic strain relief, more efficient carrier collection in thinner layers, and enhanced light trapping from nano-scale optical index changes. This hybrid structure is fabricated into working solar cells exhibiting photoresponse out to 2.1 eV and short-circuit current densities of ~1 mA cm−2 under 1 sun AM1.5G. This proof-of-concept nanowire-based device demonstrates a route forward for high-efficiency III-nitride solar cells.