Optimized resonant tunnelling structures with high conductivity and selectivity
ARC Photovoltaics Centre of Excellence, UNSW - Sydney-2052, Australia
Accepted: 13 October 2011
An improved design for double-barrier resonant tunnelling structures using silicon quantum dots (QDs) was quantitatively analyzed using a multi-mode scatter matrix method. Multilayer metal-barrier-QD/matrix-barrier-metal stacks that maximize both electron transport and confined energy are sought. Si QDs grown in silicon dioxide with silicon carbide barriers were the most advantageous combination for single QD layer double-barrier structures (DBSs). Lateral SiO2 barriers provided greater confinement, especially in smaller dots and also caused increased splitting between resonant levels. These structures are excellent candidates for use as energy selective contacts (ESCs) and as layers in all-silicon tandem cells.
PACS: 73.50.-h – Electronic transport phenomena in thin films / 73.63.-b – Electronic transport in nanoscale materials and structures
© EPLA, 2011