Large area screen printed N-type base silicon solar cells with efficiency exceeding 18%
conference paper
There is currently much interest in n-type base solar cells because of potential advantages, both of silicon base material and of cell process, for high efficiency. We present results of n-base solar cells on large area multicrystalline and monocrystalline silicon wafers, produced using simultaneous diffusion of phosphorus back surface field and boron emitter, screen-printed metallization and firing through. The cell process leads to record high efficiencies of 16.4% on multicrystalline and 18.3% on monocrystalline wafers. It is experimentally demonstrated that in multi-crystalline Si a low resistivity is correlated to reduced cell efficiency, with the optimum base resistivity lying between 1.5 and 4 Ocm. By characterizing and modeling cells from monocrystalline Si, from nominally clean multicrystalline Si, as well as from intentionally Fe-contaminated multi-crystalline Si, the impact of purity on emitter recombination is investigated in more detail.
TNO Identifier
821552
Publisher
ECN
Source title
23rd European Photovoltaic Solar Energy Conference and Exhibition, Valencia, Spain, 1-5 september 2008.
Collation
4 p.
Place of publication
Petten
Pages
4 p.
Files