Solar cells, consisting of core-shell p-n junction silicon micropillars on a thin membrane fabricated using soft lithography and metal-assisted chemical etching, are studied as a function of geometrical designs. Significant enhancement in absorption rate is found without much dependence on the pillar diameters in the range of 0.5-2 μm. However, the short-circuit current increases continuously with diameter, which is inversely proportional to the total surface area for a fixed diameter/pitch pillar array. This study provides unambiguous evidence that surface recombination is the dominant loss mechanism in nanowire- or micropillar-based solar cells.
Bibliographical noteFunding Information:
Manuscript received November 5, 2001; revised December 3, 2011; accepted December 13, 2011. Date of publication January 27, 2012; date of current version March 16, 2012. This work was supported in part by the Department of Energy Division of Materials Science under Award DEFG02-07ER46471, by the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign, and by the National Science Foundation under Award 0749028 (CMMI).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering