Scientists at Aalto University, Finland and Fraunhofer
ISE, Germany report an efficiency of 18.7% for black silicon solar
cells, the highest efficiency reported so far for a black silicon solar
cell.
The researchers were able to apply a boron diffusion to create a
pn-junction, maintaining the excellent optical properties of the black
silicon structure. By applying atomic layer deposited Al203, an
effective passivation of the nanostructured surfaces was achieved. The
previous efficiency record of 18.2% was held by the U.S. Department of
Energy’s National Renewable Energy Laboratory (NREL) using thermal
oxidation as a passivating layer.
- The quantum efficiency measurements reveal that the nanostructured
front surface is of a high electrical quality comparable to a pyramidal
textured surface, says Assistant Professor Hele Savin of Aalto University. Routes for improving the cell efficiency are already identified, and efficiencies clearly above 20% should be within reach.
The paper, ‘Passivation of Black Silicon Boron Emitters with ALD Al2O3’
by Päivikki Repo, Ville Vähänissi, Guillaume von Gastrow, Jan Benick,
Jonas Schön, Bernd Steinhauser, Martin C. Schubert and Hele Savin, was
presented in SiliconPV, the 3rd International Conference on Crystalline
Silicon Photovoltaics, 25-27 March 2013 in Hamelin, Germany.
More information:
Research Scientist Päivikki Repo
Aalto University
Tel. +358 50 436 1156
Assistant Professor Hele Savin
Aalto University
Tel. +358 50 541 0156
